Visual Presentations, Executive Lounge Hall

SolarTR is a biannual solar energy event organized alternately by involved organizations (or by
Turkish Photovoltaic Technology Platform). The 2012 event is organized as a joint event by UFTP
– Turkish PV Technology Platform, EÜ-GEE – Ege University Solar Energy Institute and GÜNAM –
The Center for Solar Energy Research and Applications.
International SolarTR-2 Solar Electricity Conference and Exhibition become possible with the
moral and material support and various contributions made by our cooperative public
organizations: Antalya Metropolitan Municipality, Antalya Chamber of Commerce and Industry,
Ministry of Energy and Natural Resources.
1
2
Chairman's Message
Dear Solar Energy Community,
Welcome to the SolarTR-2 organization.
Renewable energy sources are becoming more and more important in recent
years because of the increasing energy demand and environmental problems
caused by fossil fuels in Turkey and in the rest of the world. Among these
sources, solar energy is the only energy kind that has the potential to supply the increasing energy demand of
our society.
Turkey is expected to be one of the major countries making use of solar energy in the coming years because
of its high energy potential in its geography. Turkish parliament has adapted a new law to provide support
and incentives to the producers and users of solar energy. The organization of SolarTR-2 coincides with the
efforts to implement this important incentive law.
SolarTR-2 is organized in the beautiful city of Antalya where the sun is shining for both energy generation and
enjoyment of life in the beautiful coastal area of the city. Invited speakers, innovative companies and decision
makers (politicians, government officials) are participating in this event. One of the objectives of this event is
to create a platform for interaction between private companies, university researchers and government
officials for further R&D and production in Turkey.
This year, we would like to make SolarTR conference more special and international by bringing researchers
and private sector community from Turkey, Middle Eastern and North African Countries together. We
organize special activities to promote interaction between them. In particular, investment in Turkey and
Middle East, and technical aspects of these investments will be discussed.
Keynote speakers from Turkey, Middle East, North Africa and major research canters in other countries, and
companies have been invited.
Scope of the conference is:
•
Crystalline Si technologies
•
Concentrator and III-V compound technologies
•
CIGS, CdTe and related technologies
•
Thin film Si technologies (amorphous, nanocrystalline, polycrystalline)
•
Organic, dye sensitized PV technologies and new concepts
•
Measurements and characterization of PV materials and devices
•
PV Power Plants
•
CSP Plants
•
Operation and Performance for Solar Power Systems
•
Markets for Solar Electricity Systems
•
Solar City Planning and Construction
Prof. Dr. Rasit TURAN,
Chairman of SolarTR-2
3
4
Invited Speakers
•
Prof. Arthur Nozik, National Renewable Energy Laboratory (NREL), USA
•
Dr. Stefan Gall, Helmholtz Zentrum Berlin für Materialien und Energie (HZB), GERMANY
•
Prof. Hans-Werner Schock, Helmholtz Zentrum Berlin für Materialien und Energie (HZB),
GERMANY
•
Dr. Julian Perrenoud, EMPA, SWITZERLAND
•
Prof. Christophe Ballif, Ecole Polytechnique Fédérale de Lausanne, SWITZERLAND
•
Prof. M. Pınar Mengüç, Özyegin University, TURKEY
•
Prof. Mehmet Güneş, Mugla University, TURKEY
•
Prof. David Faiman, Ben-Gurion University of the Negev, ISRAEL
•
Prof. Abraham Kribus, Tel Aviv University, ISRAEL
•
Prof. Karl-Heinz Heinig, Helmholtz Zentrum Dresden Rossendorf (HZDR), GERMANY
•
Dr. Ivan Gordon, IMEC, BELGIUM
•
Dr. Bülent Başol, CTO, Founder EncoreSolar, San Jose, California, USA
5
6
7
Organization Committee
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Prof. Dr. Raşit Turan, Center for Solar Energy Research and Application, Middle East Technical
University (ODTÜ-GÜNAM)
Prof. Dr. Sıddık İçli, Solar Energy Institute, Ege University
Prof. Dr. Metin Çolak, Turkish PV Technology Platform (UFTP)
Prof. Dr. Şener Oktik, GENSED
Prof. Dr. Aynur Eray, Hacettepe University
Prof. Dr. Nilüfer Eğrican, International Center of Applied Thermodynamics (ICAT)
Prof. Dr. Çiğdem Erçelebi, Middle East Technical University
Prof. Dr. Pınar Mengüç, Özyeğin University
Prof. Dr. Bülent Yeşilata, Harran University
Prof. Dr. Macit Özenbaş, Middle East Technical University
Prof. Dr. Mehmet Parlak, Middle East Technical University
Prof. Dr. Süleyman Özçelik, Gazi University
Prof. Dr. Atilla Aydınlı, Bilkent University
Prof. Dr. Engin Türe, GENSED
Prof. Dr. Mimoun Zazoui, Chair of the Moroccan Society of Renewable Energy, Morocco
Prof. Dr. Ahmad Galal, Cairo University, Egypt
Assoc. Prof. Dr. Canan Varlıklı, Solar Energy Institute, Ege University
Assoc. Prof. Dr. Engin Özdemir, Kocaeli University
Assoc. Prof. Dr. Alp Osman Kodolbaş, The Scientific and Technological Research Council of Turkey National Metrology Institute (TÜBİTAK-UME)
Assoc. Prof. Dr. Haydar Livatyalı, The Scientific and Technological Research Council of Turkey –
Marmara Research Center (TÜBİTAK-MAM)
Assoc. Prof. Dr. Ceylan Zafer, Solar Energy Institute, Ege University
Assist. Prof. Dr. İbrahim Atmaca, Akdeniz University
Assist. Prof. Dr. Özge Tüzün Özmen, Düzce University
Assoc. Prof. Dr. Şule Erten Ela, Solar Energy Institute, Ege University
Assist. Prof. Dr. Alpan Bek, Middle East Technical University
Assoc. Prof. Dr. Rezek M. S. Mohammad, Palestine Technical University, Palestine
Assist. Prof. Dr. Bircan Dindar, Solar Energy Institute, Ege University, TURKEY
Dr. Mete Çubukçu, Solar Energy Institute, Ege University
Dr. Baha Kuban, UFTP
Dr. Haitham Abu-Rub, Texas A&M University at Qatar
Maher Soueidan, National Council For Scientific Research, Lebanon
İlker Ongun, Ege University
Engin Erarslan, Antalya Metropolitan Municipality
Elif Sarı, Antalya Metropolitan Municipality
Mustafa Karabağır, Antalya Chamber of Commerce and Industry (ATSO)
Mürşat Özkaya, İstanbul Chamber of Industry
Dr. Ersin Özsan,Teksolar Co., United Kingdom
Dr. Bülent Başol, EncoreSolar, Fremont, California, USA
Fırat Salmanoğlu, Solar Energy Institute, Ege University
8
Scientific Committee
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
T.M. Razykov, Uzbek Academy of Sciences, UZBEKISTAN
Sam-Shajing Sun, Norfolk State University, USA
Arturo Morales-Acevedo D.F., MEXICO
M. S. A. Abdel-Mottaleb Ain Shams University, EGYPT
F. Yakuphanoğlu, Fırat University, TURKEY
Safa Kasap, University of Saskatchewan, Saskatoon, CANADA
Mario Tucci, ENEA, Rome, ITALY
Serdar Sarıçiftçi, Johannes Kepler Universität Linz, AUSTRIA
Michael Graetzel, Swiss Federal Institute of Technology, SWITZERLAND
Dr. Rommel Noufi, NREL, USA
Prof. Al Compaan University of Toledo, USA
Dr. Bhushan Sopori, NREL, USA
Prof. Ayodhya Tiwari, EMPA, SWITZERLAND
Prof. Hans Werner Schock, Hahn-Meitner Institut, GERMANY
Dr. Mowafak El Jassim, NREL, USA
Prof. Neelkant Dhere, Florida Solar Energy Center, USA
Prof. Tokio Nakada, Aoyama Gakuin University, JAPAN
Assoc. Prof. Dr. Kasim Ocakoğlu, Mersin University, TURKEY
A.A.M. Sayigh, Editor-in-chief, Renewable Energy
Moustafa Y.Ghannam, EE Department, College of Engineering and Petroleum, KUWAIT
M. Bouaicha, Centre de Recherches et des Technologies de l’Energie, Technopole de Borj-Ce´dria,
TUNISIA
Prof. Dr. Raşit Turan, Center for Solar Energy Research and Application, Middle East Technical
University (ODTÜ-GÜNAM), TURKEY
Prof. Dr. Sıddık İçli, Solar Energy Institute, Ege University, TURKEY
Prof. Dr. Metin Çolak, Turkish PV Technology Platform (UFTP), TURKEY
Prof. Dr. Şener Oktik, UFTP, TURKEY
Prof. Dr. Aynur Eray, Hacettepe University, TURKEY
Prof. Dr. Nilüfer Eğrican, International Center of Applied Thermodynamics (ICAT), TURKEY
Prof. Dr. Çiğdem Erçelebi, Middle East Technical University, TURKEY
Prof. Dr. Pınar Mengüç, Özyeğin University, TURKEY
Prof. Dr. Bülent Yeşilata, Harran University, TURKEY
Prof. Dr. Macit Özenbaş, Middle East Technical University, TURKEY
Prof. Dr. Mehmet Parlak, Middle East Technical University, TURKEY
Prof. Dr. Süleyman Özçelik, Gazi University, TURKEY
Prof. Dr. Mustafa Güneş, Solar Energy Institute, Ege University, TURKEY
Assoc. Prof. Dr. Canan Varlıklı, Solar Energy Institute, Ege University, TURKEY
Assoc. Prof. Dr. Şule Erten Ela, Solar Energy Institutute, Ege University, TURKEY
Assoc. Prof. Dr. Engin Özdemir, Kocaeli University, TURKEY
Assoc. Prof. Dr. Alp Osman Kodolbaş, The Scientific and Technological Research Council of Turkey National Metrology Institute (TÜBİTAK-UME), TURKEY
Assoc. Prof. Dr. Haydar Livatyalı, The Scientific and Technological Research Council of Turkey –
Marmara Research Center (TÜBİTAK-MAM), TURKEY
Assoc. Prof. Dr. Ceylan Zafer, Solar Energy Institute, Ege University, TURKEY
Assoc. Prof. Dr. A. Sertap Kavasoğlu, Muğla Sıtkı Koçman University, TURKEY
Assoc. Prof. Dr. Mahmut Kuş, Selçuk University, TURKEY
Assist. Prof. Dr. Bircan Dindar, Solar Energy Institute, Ege University, TURKEY
Assist. Prof.Dr. Rüştü Eke, Muğla Sıtkı Koçman University, TURKEY
9
SOLARTR-2: SOLAR ELECTRICITY CONFERENCE AND EXHIBITION PROGRAMME
Tuesday, 6 November 2012
16:00-18:30
Registration
Wednesday, 7 November 2012
07:30-09:00
Registration
OPENING CEREMONY, ALADAĞ HALL
09:00-09:10
Prof. Raşit Turan, Chairman of SolarTR-2
Director, Middle East Technical University - The Center for Solar Energy Research and Applications
(GÜNAM), TURKEY
09:10-09:20
Prof. Sıddık İçli, UFTP Project Coordinator, Ege University Solar Energy Institute, TURKEY
09:20-09:30
Prof. Günnur Koçar, Director, Ege University Solar Energy Institute, TURKEY
09:30-09:40
Prof. Şener Oktik, Chairman, Solar Energy Industry and Tradepersons Association (GENSED),
TURKEY
09:40-09:50
Çetin Budak, Chairman, Antalya Chamber of Commerce and Industry (ATSO), TURKEY
09:50-10:00
Prof. Mustafa Akaydın, Mayor, Antalya Metropolitan Municipality, TURKEY
10:00-10:30
Plenary talk : (Invited) Prof. Arthur Nozik, NREL, USA
Approaches to Future Generation Photovoltaics and Solar Fuels: Multiple Exciton Generation in
Quantum Dots, Quantum Dot Arrays, Molecular Singlet Fission and Quantum Dot Solar Cells
10:30-11:00
Coffee Break
SESSION 1: Crystalline Si Solar Cell Technologies, ALADAĞ HALL
SEMINAR, PULLPINAR HALL
Chair: Prof. Şener Oktik, Şişecam Co., TURKEY
11:00-11:30
(Invited) – Dr. Ivan Gordon
IMEC, BELGIUM
Local Governments Session:
A cell-module Integration Concept to Fabricate Ultra-thin cSustainability and Renewables
Si Layers on Glass into Interdigitated Back-contact Solar
(in Turkish)
Modules
11:30-11:45
Dr. Junegie Hong
(11:00-12:30)
Air Liquide, FRANCE
Precursor Gases and Liquids for High Performance
Crystalline Si Solar Cells
11:45-12:00
Prof. Ali Rostami*, Hamid Heydarzade, Dr. Hamed Baghban,
Dr. Hassan Rasooli, Dr. Mahbube Dolatyari
*University of Tabriz, IRAN
Yerel Yönetimler Oturumu:
Introducing High Efficiency Solar Cells Based on Crystalline
Sürdürülebilirlik ve Yenilenebilir
Silicon Doped with Transition Metals
Enerji
12:00-12:15
Fırat Es
GÜNAM-METU, TURKEY
(11:00-12:30)
Application of Si Nanowires to Mono and Multicrystalline
Solar Cells
12:15-12.30
Dr. Robin Nissler
Schmid Group, GERMANY
Multi-busbar Metallization
12:30-14:00
Poster, EXECUTIVE LOUNGE HALL
12:30-14:00
Lunch
10
UFTP Seminar / UFTP Semineri
LOCAL GOVERNMENTS SESSION: SUSTAINABILITY AND RENEWABLES (in Turkish)
YEREL YÖNETİMLER OTURUMU: SÜRDÜRÜLEBİLİRLİK VE YENİLENEBİLİR ENERJİ
7 Kasım 2012
DEDEMAN ANTALYA HOTEL - PULLPINAR HALL
Konuşmacılar: Engin ERARSLAN, Dr. Baha KUBAN, Dr. Mete ÇUBUKÇU, İlker ONGUN, Caner DEMİR
11:00 - YEREL YÖNETİMLER İKLİM MÜZAKERELERİNDE
–
–
–
–
Dünya ölçeğinde yerel yönetimlerde sürdürülebilir enerji planlama ve uygulama
faaliyetleri
Kent Ölçeğinde Neler Yapılabilir – Dünya Kentlerinden Örnekler?
Kentlerde yenilenebilir enerji uygulamalarının kilidi; akıllı ve mikro-şebekeler, enerji
tedarik altyapısının dönüşümü
Kentler ve İklim Değişikliği İlişkisi
12:30 – ÖĞLE YEMEĞİ
14:00 – TEMEL SERA GAZI ENVARTERİ
•
•
•
Karbon kredilerinin yerel yönetimlerdeki yenilenebilir enerji uygulamalarına katkısı ne
olabilir?
Temel Sera Gazı Envanteri Hesaplamaya Giriş
– Kentler Neden Sera Gazı Envanteri Hazırlamalı?
– Kentlerde Sera Gazı Hesaplama Yöntemleri?
– Envanterin Faydaları / Dünyadan Örnekler
– Envanter Hesaplamanın Adımları, Envanter Hazırlanmasında Kapsam ve Sınırların
Belirlenmesi, Veri Toplanması, Planlanması ve İşlenmesi
– Azaltım Hedeflerinin Belirlenmesi
SORU VE CEVAPLAR
15:30 - KAPANIŞ
11
12
SESSION 2A: a-Si Thin Film and Heterojunction
Si Technologies, ALADAĞ HALL
Chair: Prof. Aynur Eray,
Hacettepe University, TURKEY
14:00-14:30
(Invited) – Prof. Christophe
Ballif
EPFL, SWITZERLAND
Silicon Photovoltaic Based on
Thin Film and on
Heterojunction Technology:
Current Status and Future
Developments
14:30-14:45
(Invited) Prof. Mehmet Güneş
Muğla Sıtkı Koçman University,
TURKEY
Investigation of Instability
Effects in Photovoltaic Thin
Film Silicon Materials by the
Dual Beam Photoconductivity
Spectroscopy
14:45-15:00
Reza Zehtaban
OERLIKON Solar,
SWITZERLAND
Technology and PV, Made in
Turkey
15:00-15:15
Engin Özkol
GÜNAM-METU, TURKEY
New Cluster PECVD system at
GÜNAM
15:15-15:30
Ms. Özlem Pehlivan*, Okan
Yılmaz, Dr. Alp Osman
Kodolbaş, Dr. Özgür Duygulu,
Prof. Mehmet Tomak
*TÜBİTAK- National Metrology
Institute (UME), TURKEY
Structural Characterization Of
Intrinsic a-Si:H Thin Films For
Silicon Heterojunction Solar
Cells
15:30-15:45
15:30-16:00
SESSION 2B: Measurement and
Characterization, TOROS 1 HALL
Chair: Dr. Ceylan Zafer,
Ege University, TURKEY
SEMINAR,
PULLPINAR HALL
Local Governments
Session: Sustainability
and Renewables
(in Turkish)
(14:00-15:30)
Andreas Kühlen
ATLAS MTT Gmbh, GERMANY
Improved Measurement
Techniques for Solar Energy
Systems
Andreas Cox
TÜV Energie und Umwelt GmbH,
GERMANY
Special Requirements for
Measurement and Testing of PVT
Hybrid Modules
Dr. Hala Abd El Megeed*, Dr. Ali
El Rifaie
*National Institute for Standards,
EGYPT
Validation of a New Measuring
System for Performance
Evaluation of a Large Solar
Module in a Desert Area
Dr. Fawzy Mahmoud*, Prof. Adel
Basiouny Shehata
National Research Center, EGYPT.
Preparation and Characteristics
of MEH-PPV for Solar Cell
Application
Levent Yalçın
Turkish State Meteorological
Service
Performance Comparison of
Mono, Multi and Amorphous PV
by PVSYST in Ankara Terms
Coffee Break
13
Yerel Yönetimler
Oturumu:
Sürdürülebilirlik ve
Yenilenebilir Enerji
(14:00-15:30)
14
SESSION 3A: a-Si and c-Si Thin Film Technologies,
SESSION 3B: Operation and
ALADAĞ HALL
Performance, TOROS 1 HALL
Chair: Prof. Mehmet Güneş,
Chair: Prof. Metin Çolak,
Muğla Sıtkı Koçman University, TURKEY
UFTP, TURKEY
16:00-16:15 (Invited) Dr. Stefan Gall
Helmholtz-Zentrum Berlin für
16:15-16:30 Materialien und Energie, GERMANY Harun Girgin
Polycrystalline Si Thin-Film Solar
AnelEnerji Co., TURKEY
Cells on Glass – Challenges and
Photovoltaic Solar Power Plant Design
Opportunities
Criteria and System Reliability
16:30-16:45 Mehmet Karaman*, Salar Habibpur Dr. Engin Özdemir*, Ahmet Aktaş, Dr.
Sedani, Dr. Kadir Erturk, Gizem
Abdulhakim Karakaya, Dr. Mehmet
Nogay, Prof. Raşit Turan
Uçar
*GÜNAM-METU, TURKEY
*Kocaeli University, TURKEY
Operation and Performance of Grid
Fabrication and Doping Thin Film
Connected Solar Photovoltaic Power
Crystalline Si by Electron Beam
System in Kocaeli University
Evaporation for Solar Cell
Applications
16:45-17:00 Prof. Aynur Eray*, Melis Bilgiç
Dr. Gökay Bayrak*, Ali Atilla Uslu,
Aksarı, Dr. Giuseppe Nobile
Gürel Nedim Örnekçi, Prof. Mehmet
*Hacettepe University, TURKEY
Cebeci
Simulation Studies on
*Fırat University, TURKEY
Hydrogenated Amorphous Silicon
An Off Grid Photovoltaic System
Solar Cells.
Design for Fish Cages in Farms
17:00-17:15 Zaki Saleh*, Salam Kmail, Samah
Bedrettin Uzun*, Gülin Acarol Zilanlı,
Assaf, Prof. Atef Qasrawi
Ömer Akan, Prof. Aynur Eray
*Arab American University-Jenin,
*Hacettepe University, TURKEY
PALESTINE
Investigation of Performance for
Recombination Mechanisms in Low Fixed-Inclined, One Axis and Two-Axis
Impedance Hydrogenated Silicon
Tracking Photovoltaic System in
Nano-crystalline Thin Films
Different Parts of Turkey
17:15-17:30 Dr. Fawzy Mahmoud*, Dr. Mostafa
Dr. Mustafa Engin
Boshta
Ege University, TURKEY
*National Research Center, EGYPT
Circuit-based Simulation Model for
Laser Ablated Nanocrystalline
Photovoltaic Panel
Silicon Thin Film for Solar Cell
Application
17:30-17:45 Dr. Ahmed Abou-Kandil*, Dr.
Gencer Sarıoğlu*, Dr. Rüştü Eke
Jeehwan Kim, Dr. Devendra K.
*Muğla Sıtkı Koçman University,
Sadana
TURKEY
*Egypt Nanotechnology Center,
Partially Shaded Characterization
EGYPT
Effect on Two Different Single
Efficiency Enhancement of a-Si:H
Crystalline Photovoltaic Modules with
Bypass Diode
Single Junction Solar Cells by the
Incorporation of Metallic Nanodots
or a-Ge:H at the p+ aSiC:H/transparent Conducting
Oxide Interface
17:45-19:00 Poster, EXECUTIVE LOUNGE HALL
19:00Cocktail, Hosted bu Antalya Metropolitan Municipality
15
SEMINAR,
PINARBAŞI 1 HALL
PV Mirror Committee
+ ATLAS Joint Event
(16:00-17:45)
Thursday, 8 November 2012
07:30-08:45
Registration
SESSION 4A: New Materials and
Concepts, ALADAĞ HALL
Chair: Prof. Atilla Aydınlı,
Bilkent University, TURKEY
08:45-09:15
09:15-09:30
09:30-09:45
09:45-10:00
(Invited) Prof. Karl-Heinz
Heinig*, Prof. Atilla
Aydinli, Prof. Rasit Turan,
Dirk Hauschild
HZDR, GERMANY.
The German-Turkish
Project RainbowEnergy:
a-Si based
Nanocomposite Absorber
for Thin Film PV Cells
Gizem Nogay*, Serim
İlday, Prof. Raşit Turan,
Prof. Karl Heinz Heinig,
David Friedrich,
* GÜNAM-METU, TURKEY
Spectroscopic
Ellipsometry Studies of
nc-Si/a-Si and nc-Si/SiO x
Systems: Optical
Characterization of
Crystallization
Dr. Mostafa El-Ashry*,
Dr. Osama Tobail
*Egypt Nanotechnology
Center (EGNC), EGYPT
Carbon Nanostructures as
Transparent Electrode for
Thin Film Solar Cells
Nilüfer Evcimen
Duygulu*, Dr. Alp Osman
Kodolbaş, Dr. Özgür
Duygulu, Prof. Ahmet
Ekerim
*Yıldız Technical
University, TURKEY
Structural, Optical and
Electrical Properties of
Zinc Oxide and Aluminum
Doped Zinc Oxide for
Photovoltaic Applications
SESSION 4B: Markets for Solar
Electricity Systems,
TOROS 1 HALL
Chair: Dr. Baha Kuban, UFTP,
TURKEY
SEMİNAR,
PULLPINAR
HALL
SEMINAR,
PINARBAŞI 1 HALL
OERLIKON SOLAR
SEMINAR
(08:45-10:45)
Dr. Lütfü Şağbanşua*, Vedat
Kıray
*Turgut Özal University,
TURKEY
Analyzing Applicability of
Solar Panel Usage with State
Support in Buildings
Grid
Connection
Issues for
Solar
Electricity
Systems (in
Turkish)
(09:15-10:45)
Hakkı Karacaoğlan*, Michael
Wollny
*SMA Solar Technology,
GERMANY
Customized Technological
Solutions for Rural
Electrification Based on
Renewables
Dr. Abdeen Omer
Energy Research Institute (ERI),
UNITED KINGDOM
Clean Energies Development
and Built Environment
Güneş
Enerjisi
Sistemlerinde
Şebeke
Bağlantısı
(09:15-10:45)
16
10:00-10:15
Dr. Ercan Balıkçı
Boğaziçi University,
TURKEY.
Single Crystal Growth of
Germanium-Silicon Alloys
(Invited) Prof. Pınar
Mengüç
Özyeğin University,
TURKEY
Near Field Radiative
Transfer: A Review
10:45-11:15 Coffee Break
SESSION 5A: CdTe/CdS and CIGS
ALADAĞ HALL
Chair: Prof. Çiğdem Erçelebi,
METU, TURKEY
11:15-11:30 (Invited) Dr. Julian
11:30-11:45 Perrenoud
EMPA, SWITZERLAND
CdTe Solar Cells in
Substrate Configuration
11:45-12:00 (Invited) Prof. Hans W.
Schock
Helmholtz Zentrum Berlin
für Materialien und
12:00-12:15
Energie, GERMANY
Current State and Future
Prospects of Thin Film
Solar Cells
10:15-10:45
12:15-12:30
12:30-12:45
12:45-14:00
12:45-14:00
Dr. Nurdan Demirci
Sankır,
TOBB University of
Economics and
Technology, TURKEY
Ultrasonic Spray
Deposition of CuInS2
Absorber Thin Films:
Effect of Nozzle
Frequency
(Invited) Dr. Bülent Başol,
CTO, EncoreSolar, San
Jose, California, USA,
Attractive Features and
Challenges for Flexible PV
Module Manufacturing
Melih Ballıkaya*, Michael Bez,
Ozan Özışık
*Yıldız Technical University,
TURKEY
A Smart Grid Approach Energy
Management with Social
Media
Selkan Polatkan,
Motif Proje, TURKEY
PV Investment Project
Development Stages in Turkey
SESSION 5B: Operation and
Performance, TOROS 1 HALL
Chair: Prof. Bülent Yeş,iata,
Harran University, TURKEY
MSc. İlker Ongun, Weighted
Efficiency Measurment of PV
Inverters: Ƞ İZMİR
Hazar Atalay
Solar Nokta, TURKEY
An Overview of CIS Based PV
Power Systems
Eşref Deniz*, Dr. Necdet Yıldız,
Dr. Numan S. Çetin
*Ege University Solar Energy
Institute, TURKEY
An Overview of MPPT
Techniques
Dr. Mete Çubukçu*, Prof. Dr.
Metin Çolak
*Ege University Solar Energy
Institute, TURKEY
Modeling, Comparative
Simulation and Practical
Performance Analysis of a
Stand-Alone PV Power System
in Turkey
Dr. Engin Özdemir*, Serkan
Sezen
Kocaeli University, TURKEY
Modeling, Simulation and
Control of Three Phase Three
Level Multilevel Inverter for
Grid Connected PV System
Poster, EXECUTIVE LOUNGE HALL
Lunch
17
SEMINAR,
PULLPINAR
HALL
SEMINAR
PINARBAŞI 1 HALL
Grid
Connection
Issues for
Solar
Electricity
Systems (in
Turkish)
AIRLIQUDE
SEMINAR
(11:15-12:45)
Güneş Enerjisi
Sistemlerinde
Şebeke
Bağlantısı
(11:15-12:45)
Air Liquide group
and presence in
Turkey
Olivier Randet,
General Manager,
Air Liquide Turkey
Air Liquide and
photovoltaic
energy
Dr Mouloud Bakli,
PhD
Global Business
Director,
Solar and
Emerging Markets,
Air Liquide World
Business Line
UFTP Seminar / UFTP Semineri
GRID CONNECTION ISSUES FOR SOLAR ELECTRICITY SYSTEMS (in Turkish)
GÜNEŞ ENERJİSİ SİSTEMLERİNDE ŞEBEKE BAĞLANTISI
8 Kasım 2012
DEDEMAN ANTALYA HOTEL - PULLPINAR HALL
Gündem
09:15 – Oturum I: Güneş Enerjisi Sistemlerinin Şebeke Bağlantısında İzlenecek Süreçler
(Başvuru – Proje Onay ve İşletmeye Alma Süreçleri).
•
Şaban Demir, Enerji Piyasası Düzenleme Kurulu (EPDK)
•
Bilal Şimşek, TEDAŞ Genel Müdürlüğü.
10:45 – KAHVE ARASI
11:15 – Oturum II: Türkiye’de Güneş Enerjisi Sektörü Durum Analizi
(Sorunlar – Riskler - İmkânlar)
•
Mustafa Atilla, Halk Enerji Yatırımları Üretim ve İnşaat A.Ş.
12:00 – Oturum III: Fotovoltaik Modüllerinin Gerçek Zamanlı Performans Analizi
(FV Modül Ömrü – İşletim Verimleri – Sahada Karşılaşılan Olası Sorunlar ve Çözümleri)
•
Hakan Çiftçi, Bosch Solar Energy AG, Almanya.
12:45 – ÖĞLE YEMEĞİ
14:00 – Güneş Enerji Sistemlerinde Şebeke Bağlantısı
•
Hakkı Karacaoğlan, SMA Solar Technology AG, Almanya.
15:30 – KAHVE ARASI
16:00 – Güneş Enerji Sistemlerinin Şebeke Bağlantısında Dikkat Edilecek Hususlar
(DA Koruma/ AA Taraflı Koruyucu Tertibatlar / Koruma Şalterleri / Şebeke Ayırıcı ve Şebeke
Bağlantısı / Topraklama Sistemi / AA Tarafındaki Koruma Tekniği Seçimi vb.)
•
•
Nevres Dabil, JUWI Solar GmbH, Almanya.
Martin Hesse, JUWI Solar GmbH, Almanya.
17:00 – SORU VE CEVAPLAR
17:30 - KAPANIŞ
18
SMA Solar Technology AG is a global leader in the development,
production and sales of PV inverters offering innovative key technologies
for future power supply structures. SMA is represented in all important
PV markets in 21 countries and has a staff of over 5 500 with a sales
volume of €1,7 billion in 2011.
The inverter is an important component of a PV plant. It converts the
direct current generated in the photovoltaic cells into an alternating
current compliant with the grid requirements, either for selfconsumption or feed-in to the power distribution grid. As an intelligent
system manager, SMA inverters monitor both the PV array and the
power distribution grid to perform important grid management functions, which are becoming increasingly important as
electricity production from renewable sources grows. SMA has been developing leading technological solutions and pioneering
trends in smart-grid area for years and is driving futuristic topics like intelligent energy management at household level, grid
integration of solar power and connecting storage facilities for more effective use of renewable energy.
SMA has an extensive range of products, which offers the right inverters for all module
types and plant sizes; from small residential systems to large scale plants, grid-connected
installations to stand-alone and backup systems. Plant monitoring/ visualization products
and energy management solutions complete the portfolio. SMA customers worldwide
benefit from comprehensive services: from support in installation and commissioning of
PV plants to quick and uncomplicated device replacement service and the free SMA
Service Line for technical questions. SMA also provide training for plant planners,
installers, electrically qualified persons and anybody interested in solar power in SMA
Solar Academy seminars. SMA has received numerous awards for its product solutions
and exceptional corporate culture. In 2011 and 2012, the company achieved first place in
the German “Great Place to Work®” competition in the category for companies with over
5 000 employees.
SESSION 6A : DSSC,
TOROS 1 HALL
Chair: Prof. Macit Özenbaş, METU, TURKEY
14:00-14:15
14:15-14:30
14:30-14:45
M. Burak COŞAR, Prof. Macit Özenbaş,
GÜNAM, Middle East Technical University,
TURKEY
Photovoltaic Performance of Bifacial Dye
Sensitized Solar Cell Using Chemically
Healed Binary Ionic Liquid Electrolyte
Solidified With Sio2 Nanoparticles
Dr. Bayram Kılıç
Yalova University, TURKEY
ZnO Nanowire Dye Sensitized Solar Cell
Dr. Haluk Dinçalp
Celal Bayar University
Novel Perylene Diimide-Benzimidazole
Type Dye Sensitization of Fullerenes for
Organic Photovoltaic Devices
19
SEMINAR,
PULLPINAR HALL
SEMINAR,
PINARBAŞI 1 HALL
Grid Connection
Issues for Solar
Electricity Systems
(in Turkish)
AIRLIQUIDE SEMINAR
(14:00-15:30)
(14:00-15:30)
Innovation and
research at Air Liquide
Junegie Hong, Senior
Technologist, Air
Liquide
14:45-15:00
15:00-15:15
Kerem Çağatay İçli*, Prof. Macit Özenbaş
*GÜNAM, Middle East Technical University,
TURKEY
Surface Modification of FTO Nanoparticles
for Enhanced Efficiency of DSSCs
Halide Diker*, Dr. Canan Varlıklı, Prof. Elias
Stathatos
*Ege University Solar Energy Institute,
TURKEY
Quasi-Solid State Dye-Sensitized Solar Cell
Applications of N-doped TiO2 Photoanodes
Güneş Enerjisi
Sistemlerinde
Şebeke Bağlantısı
AIRLIQUIDE SEMINAR
(14:00-15:30)
(14:00-15:30)
Görkem Memişoğlu*, Dr. Canan Varlıklı,
Halide Diker
*Ege University Solar Energy Institute,
TURKEY
Hybrid Ultraviolet Photodetector
Applications in the Consept of
Polyfluorene:Napthalenediimide:N-doped
Titanium dioxide
15:30-16:00 Coffee Break
SESSION 7A: Organic solar cells,
SESSION 7B: Plasmonics
SEMINAR,
YILDIZ HALL
and light trapping,
PULLPINAR HALL
Chair: Prof. Sıddık İçli, Ege University,
TOROS 1 HALL,
15:15-15:30
TURKEY
16:00-16:15
16:15-16:30
Dr. Ali Çırpan
GÜNAM, Middle East
Technical University,
TURKEY
Organic Solar Cells with
Benzotriazole-Based
Conjugated Copolymers
as Electron Donors
Dr. Elif Altürk Parlak
TÜBİTAK- National
Metrology Institute
(UME), TURKEY
Organic Solar Cells
Chair: Prof. Karl-Heinz Heinig,
Helmholtz Zentrum Dresden
Rossendorf (HZDR),
GERMANY
Dr. Alpan Bek*, İrem
Tanyeli, Hisham Nasser,
Fırat Es, Prof. Raşit Turan
* GÜNAM, Middle East
Technical University,
TURKEY
Structural and optical
properties of Ag
nanoparticles formed by
dewetting on various
substrates
Dr. Kürşat Şendur*, Umut
Tok
*Sabanci University,
TURKEY
Engineering the
Broadband Spectrum of
Plasmonic Nanoantenna
Surfaces
20
Grid Connection Issues for Solar
Electricity Systems (in Turkish)
(16:00-17:30)
Güneş Enerjisi Sistemlerinde
Şebeke Bağlantısı
(16:00-17:30)
16:30-16:45
16:45-17:00
17:00-17:15
17:15-17:30
17:15-18:30
19:00-
Burak Gültekin*, Deniz
Ergün, Dr. Ceylan Zafer
*Ege University Solar
Energy Institute, TURKEY
A Novel Low-cost n-Type
Semiconductor for Organic
Photovoltaics: Potential
Alternative to PCBM
Dr. Ceylan Zafer*, Kadir
Demirak, M. Zeliha Yiğit,
Mustafa Can, Deniz A.
Ergün, Dr. Şerafettin Demiç
*Ege University Solar
Energy Institute, TURKEY
Photovoltaic Performance
Improvement of
Triarylamine Substituted
Quinoxaline Push-Pull
Dyes for DSSCs
Deniz Aykut Ergün*, M.
Zeliha Yiğit, Kadir Demirak,
Mustafa Can, Dr. Şerafettin
Demiç, Dr. Ceylan Zafer
*Ege University Solar
Energy Institute, TURKEY
Molecular Engineering of
New Quinoxaline Based
Acceptors to Improve
Charge Generation in
Organic Photovoltaics
Dr. Gürsoy B. Akgüç*, Prof.
Oğuz Gülseren, Mehmet Can
Gunendi
Bilkent University, TURKEY
Understanding the Realistic
Plasmonic Properties of
Dewetting Formed Ag
Nanoparticles in Large Area
Solar Cell Applications
Seval Sarıtaş*, Dr. Emel
Sungur Özen
*Bilkent University, TURKEY
Plasmonic Nanoparticles for
Photovoltaic Applications
Dr. Selçuk Yerci*, Dr.
Anastassios Mavrokefalos,
Sang Eon Han, Gang Chen
*Massachusetts Institute of
Technology (MIT), USA
Efficient Light-Trapping in
Inverted Nano-Pyramid Thin
Crystalline Silicon
Membranes for Solar Cell
Applications
M.Ali Olgar*, H. Saglam, S.
Yazici, A. Cantas, M. Kurt, G.
Aygun, Prof. Ekrem Yanmaz,
Prof. Lütfi Özyüzer
*Karadeniz Technical
University, TURKEY
Deposition and
Sulfurization Processes of
CZTS Absorber Layer on Mo
and W Coated SLG for Solar
Cells
Poster, EXECUTIVE LOUNGE HALL
GALA DINNER
21
Grid Connection Issues for Solar
Electricity Systems (in Turkish)
(16:00-17:30)
Güneş Enerjisi Sistemlerinde
Şebeke Bağlantısı
(16:00-17:30)
TestOne Technology Solutions is a distributor company for test and
measurement equipment and consumables. With our engineers, we offer
all sales and aftersales services throughout Turkey. We represent well
known manufacturers from all over the world like;
• Hioki
• SVCS
• EKO
We are reselling product ranges of;
• Horizontal Batch Diffusion Furnaces
• Power Analyzer for Solar Applications
• Solar Radiation and Photonic Sensors
• Photovoltaic Evaluation Systems
• Metrel
• Raytech
• Ariadna
• High Voltage Diagnostics
• Vanguard Instruments
• Red Phase
• Impedance Analyzers
• LCR Meters
• Component Testing Devices
• Field Measurement Instruments
• Kikusi
• Voltech
• Zera Phoenix
• Transformer Tester
• Motor Analysis Devices
• Data Loggers
• Power Supplies
SVCS Process Innovation designs and
manufactures batch horizontal diffusion and LPCVD furnaces for
the semiconductor and PV industries. Other products include
various gas source systems like gas cabinets, valve manifold
boxes and custom equipment gas manifolds. The heart of all
SVCS tools is in-house designed control system that is often
used for refurbishment of third party equipment.
SVCS is based in Czech Republics and supported by SVCS local
offices and distributors in China, Taiwan, Russia, India, Korea,
Malaysia, Turkey and other European countries. SVCS
participates in the EU-funded research programs to achieve
higher solar cell efficiency. SVCS was awarded as the best
exporter of 2009 in the SME sector in DHL/HSBC contest
supported by the Czech ministry of the Industry and Trade.
22
Friday, 9 November 2012
08:15-09:15
Registration
SESSION 8 – Present and Future of Solar energy in MENA Countries and Turkey, ALADAĞ HALL
Chair: Prof. Mimoun Zazoui, Chair of the Moroccan Society of Renewable Energy, MOROCCO
Dr. Fedaa Ali
Qatar Energy and Environment Research Institute, QATAR
Cost and Efficiency to Achieve Grid Parity
09:30-09:45 Dr. Osama Tobail
Egypt Nanotechnology Center (EGNC), EGYPT
Potential of Photovoltaic Industry in Egypt
09:45-10:00 Dr. Mouloud BAKLI
Air Liquide Electronics, FRANCE
Global PV Market Overview / Zoom on MENA and Mediterranean
10:00-10:15 Dr. Baha Kuban
Turkish PV Technology Platform (UFTP), TURKEY
Economic Impacts of the Renewable Energy Sector; Supply Chain Approaches and the Search
for Methodology
10:15-10:30 (Invited) Prof. David Faiman
Ben-Gurion University , ISRAEL
Israel and Turkey: Case studies for the massive introduction of renewables
10:30-11:00 Coffee Break
SESSION 9A: Concentrated PV Systems,
Session 9B : Joint Session with EPHESTUS & CSP,
ALADAĞ HALL
TOROS 1 HALL
09:15-09:30
Chair: Dr. Bülent Başol, EncoreSolar,USA
11:00-11:30 (Invited) Prof. David Faiman
Chair: Dr. Haydar Livatyalı, TÜBİTAK-MAM, TURKEY
Ben-Gurion University, ISRAEL
Photovoltaics and Global GHG Reduction
11:30-11:45
11:45-12.00
Prof. Ali Rostami*, Hamid Heidarzadeh,
Dr. Hamed Baghban, Dr. Hassan Rasooli,
Dr. Mahboubeh Dolatyari
*University of Tabriz, IRAN
Thermal Stability Analysis of
Concentrating Single-Junction Silicon and
3C-SiC-based Solar Cells
Dr. Rezek M. S. Estaiteh*, Prof. Şenay
Katırcıoğlu
*Palestine Technical University,
PALESTINE
A Comparative Study for Structural and
Electronic Properties of AlN Compound
23
(Invited) Prof. Abraham Kribus
Tel Aviv University, ISRAEL
High Performance Solar Thermal Electricity
Generation
12:00-12:15
Özgür Selimoğlu
GÜNAM-METU, TURKEY
Horizontally Staggered Light Guides for
High Concentration CPV Applications
*Renewable Energy Organization of Iran & Shiraz
University, IRAN
Experimental and Numerical Analysis of Shiraz
Solar Thermal Power Plant Performance during
2009-2011
Can Uçkun
GÜNAM-METU, TURKEY
Modeling and Simulations of Direct Steam
Generation Solar Thermal Power Plant
12:15-12:30
12:30-14:00
12:30-14:00
Mr. Peyman Kanan*, Ali Rahmatmand,
Mahmood Yaghoubi, Moslem Raesi, Iman Niknia
Poster, EXECUTIVE LOUNGE HALL
Lunch
ENISOLAR Energy Ltd. has been founded by Mr. Enis
Fakioglu (BSc. Materials Science and Engineering) in
2000.
In 2007, Mr. Murat Deligöz (BSc. Electric &
Electronics Engineer) joined the company as partner,
and company succeeded to implement two
photovoltaic systems which have been the largest
installations up to that time in Turkey.
ENISOLAR entered wind measurement and assessment business in 2008, by acquiring GENBA property
and brand rights, one of the oldest and well known engineering companies in Turkey.
Apart from the partners of the company, ENISOLAR team consists of three more Physics Engineers, two
office staff, one foreman, and nine installation staff, all with “work at height” and Industrial Rope Access
Trade Association - IRATA certificates.
ENISOLAR operates under Quality Management System ISO9001:2008.
ENISOLAR team also has beeen trained by Deutsche Windguard GmbH, under Quality Management
System ISO/ IEC17025 for “site inspection for bankable energy yield assessment studies”.
ENISOLAR is a founding member of GENSED (Association of Turkish Solar Energy Businessmen and
Industry) ENISOLAR is also a member of UFTP (National Photovoltaic Technology Platform)
24
SESSION 10: SOLARTR-2 and EPHESTUS Joint Session,
ALADAĞ HALL
TECHNICAL TOUR
Chair: Prof. Abraham Kribus, Tel Aviv University, ISRAEL
14:00-14:10
14:10-14:20
14:20-14:40
14:40-15:00
15:00-15:30
15:30-16:00
16:00-16:20
16:20-16:40
16:40-17:00
17:00-17:30
17:30-17:45
17:45-18:15
18:30
Opening Speech, Prof. Raşit Turan, GÜNAM-METU, Visit to the ANTALYA SOLAR
TURKEY
HOUSE & ANTALYA AQUARIUM
Project Introduction (CRR)
Project Scientific Value (CNR- Scientific
Coordinator)
The Core of Ephestus Project: the Conversion
Module (including the theoretical potential
compared to other solar converters; by CNR)
Materials Synthesis and Test Results* (by CNR and
TUBITAK MAM)
Coffee Break
Laboratory Test Results of TAU (by TAU)
Visit to the ANTALYA SOLAR
HOUSE & ANTALYA AQUARIUM
CM Tests on the Solar Test Platform (by SHAP and
CNR)
Design and Analysis of the Cable System (by
Prysmian)
Future Prospects; Discussions (including the future
applicability of the technology ıncluding remaining
challenges and development steps; by CNR)
Break
SolarTR-2 Plenary Closing Session, ALADAĞ HALL
Chair: Prof. Raşit Turan, SolarTR-2 Chair, GÜNAM – METU, TURKEY
Visit to the ANTALYA AQUARIUM
Nurol Holding Company provides qualified
service with high technology in various sectors
such as engine, manufacturing, defence
industry, energy, technology, finance, real
estate, tourism and especially in construction
undertaking sectors in Turkey and all over the
world. Nurol with over 40 companies and with
approching 20.000 employees pays attention to
create a value and to tranfer its knowledge to
the projects realised with its powerful source
structure and experience. www.nurol.com.tr
Nurol R&D Company is progressing to be the most powerful EPC company in the growing and
prosperous market through its powerful financial structure and reliance to the company. Having signed
to significant projects in Middle East and in Turkey, Nurol is going to provide service by converting the
reliance from the regional countries to advantage in solar energy field with the help of its regional
partners.
25
TEKNOTIPAnalytical Systems is a dynamic, young company
dedicated to helping its customers touch with high--‐tech,
innovative, state-of-the-art technologies. Depending on the
power of strong partnerships with World’s leading providers, it
serves analytical solutions in the fields of Physics, Chemistry,
Biology, Material Sciences and Nanotechnology to meet or
exceed our country standards required by industrial and
academic users. With its experienced application scientists and
Experimental analysis laboratories, it also provides complete
facilities for World of Science.
Product line includes worldwide-accredited fast, robust and
accurate systems:
• Surface metrology, modifica.on and analyzing systems
(AFM, STM, SEM, TEM, Elipsometers, Op.cal and Stylus
Profilometers), Lithography systems (Mask Aligner and
Mask-less Lithography), Plasma coa.ng and etching
systems,
• Laser devices,
• Solar Simulators and Quantum Efficiency Systems
• Cryogenics,
• Chromatography,
• Spectrophotometers, etc.
For more informa.on and technical details, visit our website at
www.tekno.p.com.tr
TKI provides material testing solutions to various industrial sectors such
as textile, polymer, automotive and paint since 1987. Company business
is based on representation of multinational manufacturers listed below:
1- ATLAS Material Testing Technology GmbH (ABD, Germany): Textile, automotive, plastics and paint industry
laboratory equipment.
2- KH Steuenagel – Lichttechnik GmbH (Germany): Solar climatic cabinets
3- SDL-ATLAS LTD. – (UK): Textile test machines in a wide range
4- HERAEUS Noblelight Gmbh (Germany): Industrial type ınfrared resistances for heating & drying
5- Testfabrics Inc. (ABD): Textile laboratory consumables
ATLAS Company which we represent has pioneered innovations paving the
way for companies to test the durability of their products. Advanced Atlas
technology for accelerated weathering equipment and services, provides
the customers with sophisticated and advanced testing solutions to
determine how long their products will last. As a result, the end users will reach their ultimate goals – a product of
high quality, a competitive edge, a faster time to market.
As ETKI and as a long lasting representative of ATLAS, our main goal is to provide the weathering & lightfastness
equipment and spare parts of ATLAS, to make proper installations of the systems, offer trainings for the technical
staff, deliver aftersales technical support and to supply the required test materials and consumables for your
standards. In all these years in the market, we established a good background and knowledge of solar simulation
applications.
26
Abstracts
Session 1: Crystalline Si Solar Cell Technologies, ALADAĞ HALL
Approaches to Future Generation Photovoltaics and Solar Fuels: Multiple Exciton Generation
in Quantum Dots, Quantum Dot Arrays, Molecular Singlet Fission, and Quantum Dot Solar
Cells
A. J. Nozik†*, M.C. Beard, J.C. Johnson, M.C. Hanna, J. M. Luther, O. Semonin, A. Akdag*, and J. Michl
National Renewable Energy Laboratory, USA
*Department of Chemistry and Biochemistry, Department of Physics, University of Colorado,
Department of Chemistry, Middle East Technical University, Ankara, Turkey
One potential, long-term approach to more efficient future generation solar cells is to utilize the unique properties
of quantum dots (QDs) and quantum rods (QRs) and unique molecular chromophores to control the relaxation
pathways of excited states to produce greatly enhanced conversion efficiency through efficient multiple electronhole pair generation from single photons . We have observed efficient multiple exciton generation (MEG) in PbSe,
PbS, PbTe, and Si QDs and efficient singlet fission (SF) in molecules that satisfy specific requirements for their
excited state energy level structure to achieve carrier multiplication. We have studied MEG in close-packed QD
arrays where the QDs are electronically coupled in the films and thus exhibit good transport while still maintaining
quantization and MEG.. We have developed simple, all-inorganic QD solar cells that produce large short-circuit
photocurrents (>25 ma/cm2) and relatively high power conversion efficiencies for both nanocrystalline Schottky
junctions and nanocrystalline p-n junctions. These solar cells also show for the first time quantum yields (QYs) for
photocurrent that exceed 100% in the photon energy regions of the solar spectrum where MEG is possible; the
photocurrent MEG QYs as a function of photon energy match those determined via ultrafast time-resolved
spectroscopy. We have also observed very efficient SF in thin films of molecular crystals of organic molecules with
quantum yields of 200% at the optimum SF threshold of 2Eg (HOMO-LUMO for S0-S1)), reflecting the creation of
two excited triplet states from the first excited singlet state. Various possible configurations for novel solar cells
based on MEG in QDs and SF in molecules that could produce high conversion efficiencies will be presented, along
with progress in developing such new types of solar cells. Recent analyses of the effect of MEG or SF combined
with solar concentration on the conversion efficiency of solar cells will also be discussed.
Precursor gases and liquids for high performance crystalline Si solar cells
Dr. Junegie Hong*, Air Liquide, France
*[email protected]
In this paper, we present a review of precursor gases and liquids for a variety of thin-film applications in high
performance crystalline Si solar cells. Developing and engineering functional thin-film materials are essential in
order to achieve a high performance in crystalline Si solar cells. Various oxide and nitride layers have been
deposited from precursor gases and liquids by PECVD (plasma enhanced chemical vapor deposition) and ALD
(atomic layer deposition) methods for applications of optical coatings, front-side and rear-side surface passivation
layers, bulk passivation layers, capping layers, diffusion layers, barrier layers, and other performance boosting
functional layers. PECVD silicon carbon nitride layers were presented to reduce a light induced degradation in ptype Cz-Si solar cells and to enhance a low light illumination performance. Alternative precursor liquids for
aluminum oxide passivation layer for c-Si solar cells have been proposed in terms of safety and handling
maneuverability. Finally, innovative precursor gases and liquids for tomorrow’s PV materials will be presented.
Keywords: c-Si solar cell, precursor, passivation, optical coating, capping layer, silicon carbon nitride, aluminum
oxide
27
Introducing high efficiency solar cells based on crystalline silicon doped with transition metals
Prof. Ali Rostami*, MSc. Hamid Heydarzade, Dr. Hamed Baghban, Dr. Hassan Rasooli, Dr. Mahbube Dolatyari,
University of Tabriz, Iran
*[email protected]
Solar cell materials with more than one bandgap offer the possibility to increase the efficiency of the solar cell
beyond that of a single bandgap cell. In the intermediate bandgap solar cell (IBSC) an intermediate narrow metallic
band (IB) is placed in the traditional forbidden bandgap which extends the absorption spectrum. This generates
extra electron–hole pairs and thus increases the current without decreasing the output voltage and therefore
increases the quantum efficiency. Substitution of transition metal atoms (TM) in the crystalline silicon may give rise
to a type of high-efficiency photovoltaic materials with intermediate bands to absorb low energy photons. In the
present study comprehensive analysis is carried out on this kind of materials. Theoretical studies confirm the
formation of suitable mini-bands within silicon band gap by doping of transition metals in crystalline silicon. The
mini bands mainly are created by nd orbitals of the transition metals. Absorption coefficient, density of states and
band structure are three important features of the proposed materials. Here, we calculated these characteristics
for the crystalline silicon doped with TM=Ti, Zr, Hf, Cr, Mo, W, Fe, Ru, Os as candidates for presenting an isolated
partially-filled narrow bands between the valance band and the conduction band of silicon. The results show that a
crystalline silicon solar cell with an intermediate band located at 0.35 eV below the conduction band or above the
valence band can reach a limiting efficiency of 44%, improving greatly than 31% of the Shockley–Queisser limit for
the single junction Si solar cell. Ti doped silicon can be create this band above the valance band of silicon.
Keywords: High efficiency solar cells, Crystalline silicon, Intermediate bandgap solar cell
Application of Si Nanowires to mono and multicrystalline solar cells
Fırat Es*, Olgu Demircioğlu, Emine Hande Çiftpinar, Mete Günöven, Mustafa Kulakcı, Hüsnü Emrah Ünalan,
Raşit Turan, [email protected]
GÜNAM-METU, Turkey,
The crystalline Si solar cell production line at GÜNAM research group is aiming to implement new approaches to
improve the solar cell performance. Among these new approaches, light trapping structures are attracting wide
attention to decrease the reflection and transmission through a solar cell. This structure can be applied both to thin
film and crystalline solar cells to increase the collection probability. In this study, Si nanowires were fabricated on
standard solar cells using metal assisted etching (MAE) technique. The reflection from the device was reduced to
less than 5% between 350 - 750 nm. Cells were fabricated with standard processing sequence where texturing step
was varied. It has been seen that pyramid textured cells’ and nanowires textured cells’ efficiencies are close to each
other which showed the applicability of the nanowires texturing technique on mono-c silicon cells. It has been
observed that there was a decrease in the efficiency of the nanowires textured cells with increasing nanowires
length. The same observations were done also on multi-c silicon solar cells. The quantum efficiency measurements
revealed that this decrease in the efficiency was due to the poor collection in the blue region of the spectrum
which is due to increased carrier recombination. Moreover it was realized that, emitter contact formation on the
nanowires using conventional screen print metallization results in relatively higher series resistance due to
adhesive problem of printed silver paste as compare to the cell having pyramid texture.
28
Multi-Busbar Metallization of Crystalline Silicon Solar Cells
1
R. Nissler , [email protected] C. Pönisch, C. Ebert, H. Haverkamp, D. Habermann
Technology Center, Gebr. Schmid GmbH, Germany
With Ag consumption being one of the major cost drivers, cost reduction in crystalline silicon solar cell production demands
for improved metallization concepts. While conventionally two or three busbar ribbons are used to interconnect the cells,
we propose a modified design of the front electrode which features up to 15 thin busbar wires for cell interconnection. As a
consequence the effective finger length is drastically reduced leading to low series resistance even for small line cross
sections. By depositing a seed layer of Ag nanoparticles via inkjet printing followed by Ag plating, lines widths of about 40µm
can be realized. In combination with a novel tin-coating method for the rear side, which eliminates the use of Ag/Al paste,
the resulting total Ag consumption is as low as 30mg per cell. At the same time cell and module efficiencies are enhanced
due to reduced shadowing losses.
Keywords: crystalline silicon solar cells, metallization, seed and plate, Ag nanoparticles
Session 2A: a-Si Thin Film and Heterojunction Si Technologies, ALADAĞ HALL
Silicon photovoltaic based on thin film and on heterojunction technology: current status and
future developments
Prof. Christophe Ballif,
Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Microengineering (IMT), Photovoltaics and thin film
electronics laboratory, Switzerland.
In this presentation we’ll show some of the latest advancement of thin film silicon solar cells and high efficiency
crystalline silicon technologies based on the concept of heterojunction contacts.
In thin film silicon, remarkable improvement of the production technologies and novel device design should allow
for low production costs in the range of 0.35-0.4€/Wp at 10-11% module level. This should be possible without any
issues in the full supply chain, as all used materials are low cost and abundant. The lower efficiency compared to
competing technology’s needs, however, to be leveraged by clever solar park designs.
For crystalline silicon, the use of coating technologies based on ultra-thin amorphous silicon layers and thin
transparent conductive oxide allows the realization of solar cells with a limited number of process steps, with
potential for low cost at high efficiency. We’ll show how we reach over 22% in our laboratory, using simple screenprinted contacting technology. Results up to 23.5% with plated contacts are even reported, making such approach
very attractive. Indeed, the processes are now under industrialization by several companies. For instance large
cells with 15x15cm2 “standard” n-type over 21% could be achieved by Roth and Rau Switzerland and production
lines are now available for producing such cells with dedicated tools.
Eventually we’ll discuss about the role that the thin film silicon and silicon heterojunction technologies could play in
tomorrow’s electricity supply.
29
Investigation of Instability Effects in Photovoltaic Thin Film Silicon Materials by the Dual Beam
Photoconductivity Spectroscopy
Mehmet Güneş, Gökhan Yilmaz, Hamza Cansever , Vladimir Smirnov, Friedhelm Finger, Rudolf Brüggemann
[email protected]
Mugla Sıtkı Kocman University, Turkey
Forschungszentrum Jülich, Germany
Institut für Physik, Carl von Ossietzky Universität Oldenburg, Germany
Upon exposure of microcrystalline silicon (μc-Si:H) thin films to atmospheric gases these materials frequently show
metastability changes of their electronic properties. We investigated these phenomena using dark conductivity,
photoconductivity and sub-bandgap absorption spectroscopy for μc-Si:H material with a wide range of structure
compostions. μc-Si:H was deposited using VHF-PECVD at 200°C on smooth glass substrates. The microstructure of
the films was changed from amorphous (a-Si:H) to highly crystalline by adjusting the process gas silane
concentration during deposition. The crystallinity was evaluated from Raman measurements. Thickness of the
samples varies between 200nm and 350nm. Silver coplanar electrodes were evaporated on the samples with 0.5
cm length and 0.5 mm separation. Temperature dependent dark conductivity and intensity dependent
photoconductivity measurements were carried out by applying dc voltages in the Ohmic region of contacts. Subbandgap absorption spectrum was obtained by using dual beam photoconductivity (DBP) yield spectrum and
simultaneously measured transmission spectrum from the back of sample together with Ritter-Weiser fomula. DBP
measurements were done at 300K for different dc bias light intensities as previously reported. The samples were
randomly exposed to atmospheric gases by keeping them in the dark laboratory atmosphere. In addition, a
controlled exposure procedure was performed in well defined gas environments and liquids. Annealing was carried
out at 430K for 30 minutes. All measurements were done in high vacuum cryostats. We report on the application of
the DBP method to detect these changes in band gap state occupation and/or possible changes in the number of
gap states. In this study, we apply and evaluate the DBP method with its sensitivity to sub-gap absorption as a
method to monitor the above-mentioned conductivity changes and to relate them to possible changes in the subgap absorption to which the dark and photoconductivity changes can be linked. The results indicate a tendency that
for Type I microcrystalline silicon films the sub-gap absorption coefficient increases upon annealing which we
tentatively relate to an increase in the defect occupancy induced by the Fermi level shift towards the conduction
band edge. Increase of the sub-gap absorption between low DBP light bias and high bias case changes from factor
of 5 to 20 as consistent with the increase of the occupation of defect states by bias light.
30
New Cluster PECVD system at GÜNAM
Engin Özkol, Gizem Nogay, Hisham Nasser, Zeynep Demircioğlu, Serkan Kıncal, [email protected],
METU, Middle East Technical University, TURKEY
A new cluster PECVD system (called GÜNER) for amorphous and microcrystalline Si based solar cell production has
been designed by GÜNAM and produced by the Turkish company, Vaksis. The system has been installed in a Class
10000 clean room at GÜNAM. GÜNER system consists of 4 PECVD chambers (3 CCP and 1 ICP), one sputtering
chamber, one transfer and one load lock chamber. Absorber layer and the doped layers of the thin film silicon solar
cells are being deposited in PECVD chambers. The sputtering chamber has two different targets, namely
transparent conductive oxide (TCO) and back contact metal. The GÜNER system is fully operational and capable of
producing the complete solar cell stack. Turkey’s first thin film amorphous silicon solar panel having an area of 25
cm x 25 cm has been produced by this system. We have fabricated and characterized a-Si and c-Si thin films for
the purpose of system optimization and new material production. Optical emission spectroscopy (OES) is used insitu to monitor the plasma properties. Various diagnostic techniques such as surface profilometry, Raman
spectroscopy, ellipsometry, XRD, SEM have been applied to determine the physical, chemical, structural and optical
properties of the produced thin film. The defect structures of the films are investigated by the electron spin
resonance (ESR) spectroscopy which is located in METU Central Laboratory. Lastly, electrical properties have been
analyzed in collaboration with the Physics Department at the Muğla University.
Structural Characterization Of Intrinsic a-Si:H Thin Films For Silicon Heterojunction Solar Cells
MSc. Özlem Pehlivan, MSc. Okan Yılmaz, Assoc. Dr. Alp Osman Kodolbaş, Dr. Özgür Duygulu, Dr. Mehmet
Tomak, [email protected]
TÜBİTAK Ulusal Metroloji Enstitüsü (UME), Dr. Zeki Acar Cad., TUBITAK Gebze Kampusü, 41470-Gebze, Kocaeli
We have utilized ex-situ spectroscopic ellipsometry and HRTEM to characterize the optical and structural properties
of intrinsic a-Si:H thin layer that plays a key role for the improvement of the open circuit voltage in silicon
heterojunction solar cells. Intrinsic a-Si:H films were deposited on (100) p-type CZ silicon wafers by using Plasma
Enhanced Chemical Vapor Deposition (PECVD) technique in substrate temperature, RF power and deposition time
ranges: 130 °C – 225 °C, 12 mW/cm2 – 103 mW/cm2, 15 s – 1800 s, respectively. Observed changes in the
imaginary part of pseudo dielectric constant, e2, of c-Si spectrum with two peaks centered in 3.4 eV and 4.2 eV to
a-Si:H which has an intermediate spectrum with a soft peak at about 4.2 eV has been analyzed with using effective
medium approximation model.
Keywords: a-Si:H, silicon heterojunction, spectroscopic ellipsometer, dielectric constant,
31
Session 2B: Measurement and Characterization, TOROS 1 HALL
Improved Measurement & Testing Techniques for Solar Energy Systems
Andreas Kühlen - Vice President NOW Sales ATLAS MTT GmbH - Germany
Since requirements of the solar industry towards improved monitoring of solar product quality have been
increasing continuously, there is a strong demand to improve the level of sophistication of test system designs and
testing techniques.
State-of-the-art Solar Simulator concepts are nowadays a result of a comprehensive analysis of all aspects to
achieve optimized performance during a test cycle. Numerical virtual simulation based software analysis can help
to achieve better results.
Early life failures resulting from design flaws, materials or processing issues are often apparent from startup to the
first few years in service for solar modules. The requisite design qualification and approval tests such as IEC 61215
for crystalline silicon and IEC 61646 for thin films are relatively short accelerated tests which attempt to discover
these early “infant mortality” issues. A new comprehensive, multi-dimensional environmental weatherability test
program for PV modules can be a complement to the basic or extended versions of the IEC “infant mortality” tests.
This program delivers the weathering stresses representative of long-term outdoor exposure otherwise
unattainable without multi-year real-time field testing.
Special Requirements for Measurement and Testing of PVT Hybrid Modules
Andreas Cox, Dipl.-Ing. Ulrich Fritzsche, MSc. Jörg Althaus, Dipl-Ing. Matthias Bott, Dr. Werner
Herrmann, [email protected],
TÜV Energie und Umwelt GmbH Am Grauen Stein 51105 Köln Germany
The international standards IEC 61730 and IEC 61215 specify the minimum requirements for the design
qualification and type approval of flat-plate terrestrial crystalline PV modules. For solar thermal collectors, there's a
European Standard EN 12975 as well as an international standard ISO 9806 available. Within next year, both
standards will be merged to EN ISO 9806. None of the standards is taking the special features of PVT hybrid
modules into account. Especially the additional requirements regarding electrical safety won't be covered by the
existing standards. Since one year TÜV Rheinland is now working on a combined test procedure covering all
relevant electrical and thermal aspects and revering to existing standards wherever it is possible. In a first step, the
special behavior and specifications with respect to higher stagnation temperatures and hot spot behavior were
evaluated. Furthermore, an adapted thermal performance characterization procedure in addition to the standard
STC measurements was elaborated. Beside the determination of the thermal performance figures, also the ECT
(equivalent cell temperature) against the mean fluid temperature and wind speed will be determined. One main
part of the work was the including of the solar thermal test sequence into the standard IEC test procedure. There
are several tests similar described in both standards and there's no need to do them twice. Depending on the
construction of the PVT, some temperatures during climate chamber tests may need to be adapted. Especially the
electrical safety issue needs to be considered seriously. There's a close connection between an electrical and water
loop and all relevant risks need to be considered. TÜV Rheinland certifies both flat-plate PV modules according to
the above-mentioned IEC standards as well as solar thermal collectors according to EN 12975 and ISO 9806.
Furthermore there's a project planned to marge the requirements of both standards to one "PVT-Hybrid" standard.
This contribution reports on the experiences in certification, testing and research work on these hybrid products.
Keywords: PVT Hybrid Modules
32
Validation of a New Measuring System for Performance Evaluation of a Large Solar Module in
a Desert Area
Dr. Hala Abd El Megeed, Dr. Ali El Rifaie, [email protected],
National Institute for Standards Tersa El Haram-Giza, Egypt
The electrical performance of specified module consisting of four identical large area multi-crystalline silicon solar
cell units connected in series has been studied in a desert area under ambient conditions. Each cell is of area
21cm´21cm with back contact technology where the current collected by the fine finger grid is led to the back side
through 25 holes. On the back side there are 25 soldering pads for each polarity. Short circuit current and open
circuit voltage have been measured to describe the module electrical performance. Short circuit current values are
obtained by measuring the voltage developed across a known resistance using the current shunt measuring
technique to avoid the problems encountered with traditional measuring techniques. Current shunt is not only very
stable under a wide range of ambient temperatures but also it has an identical linearity equation, consequently it is
safely used in desert areas to obtain the short circuit currents. Furthermore, applying it in the solar cell measuring
circuit does not affect the cell temperature dependency due to its negligible temperature coefficient. For outdoor
measurements, the module was installed in a tilted position at the optimum angle of the location. The
measurements were carried out to assess the parameters and the output performance of this type of solar module.
Module performance as a function of both incident solar radiation and absolute air mass is demonstrated.
Moreover, the conversion efficiency of the module has been evaluated.
Keywords: multi-crystalline silicon solar , Current shunt, Electrical performance
Preparation and Characteristics of MEH-PPV for solar cell application
Assoc. Prof. Dr. Fawzy Mahmoud, Prof.Dr. Adel Basiouny Shehata, [email protected],
National research center-Egypt Solid State Physics Dept., National Research Center, P.O. 12311, Dokki, Giza, Egypt
Conjugated polymers, especially those of the poly (phenylenevinylene) (PPV) family, are promising candidates as
emission material in light emitting devices such as light emitting diodes, field effect transistors and photovoltaic
devices. In the present study, we have prepared MEH-PPV using a modified procedure and purified by new
techniques. The polymer sample was found to be soluble in common organic solvents. The structure of MEH-PPV
was confirmed by FTIR and 1H NMR. Gel permeation chromatography (GPC) analysis showed that MEH-PPV
synthesized by the present route has a molecular weight of 210000 g mol-1. TGA study shows the degradation of
MEH PPV occurs at 400 oC. The results show that the MEH-PPV synthesized by the present technique offers a
polymer with mid molecular weight and high thermal stability, which is one of the most important requirements for
the fabrication of optoelectronic device like solar cell. The optical properties were studied by photoluminescence
and UV-Vis absorption spectra of polymer solutions at different concentrations. MEH-PPV in THF. The polymer
showed almost same absorption spectra whose λmax is around 482 nm. The absorption edges of the polymer films
appear around 580 nm that was used for determining the optical band gap. The pure MEH-PPV polymer is
characterized with two main peaks at 592 nm with a much weaker red shoulder at about 636 nm.
Keywords: MEH-PPV, optical properties, structural properties
33
Performance Comparison of c-Si, mc-Si and a-Si Thin Film PV by PVsyst in Ankara Terms
Dr. Levent Yalçın, [email protected]
Department of Weather Forecasts / Turkish State Meteorological Service Ankara / Turkey
Prof. Dr. Ramazan Öztürk, [email protected]
Faculty of Agriculture / Ankara University Diskapi / Ankara / Turkey
The most known and used photovoltaic (PV) panels (% 95) in the market are mono-crystalline silicon (c-Si), multicrystalline silicon (mc-Si) and amorphous crystalline silicon thin film (a-Si) types. Solar electricity potential for all over
Ankara which is provided from measurements of Turkish State Meteorological Service, Atlas for Potential Solar
Power of Turkey (Ministry of Energy) and Solar Maps of Photovoltaic Geographical Information System (EU-JRC) is
over ~5 kWh/m2/day. Because of agricultural farms settle in country sides instead of urban areas, it is not easy to
reach electricity utility in all circumstances. Producing electricity energy needed for agricultural and daily activities in
an agricultural farm by itself provide a stand-alone structure against network failure and network interruption. Both
increasing of agricultural activities and sun radiation/sun duration in the months of spring and summer correspond
same period in the year. For this reason agricultural sector is more compatible to solar energy or photovoltaic (PV)
electricity than other sectors. In this study, a multi-functional agricultural farm which is located around Ankara
spreaded 4000 decares and installed 400 kW power in electricity is analysed. Providing of electrical demand of the
farm is simulated by PVSYST in order to comparison three different PV structures (c-Si, mc-Si and a-Si) for a gridconnected operating type of PV system in the terms of electrical performance indicators. It is aimed to identify what
the most compatible PV structure for Ankara and its environs is.
Material and method used in the study is quotation from a doctorate study called “Determination of Solar Energy
Potential and Using Possibilities for Research and Application Farm of Agricultural Faculty of Ankara University in
Haymana” which is completed in Graduate School of Applied Science of Ankara University in 2010.
Keywords: mono-crystalline silicon PV (c-Si), multi-crystalline silicon PV (mc-Si) and amorphous crystalline silicon
thin film PV (a-Si), photovoltaic, solar energy potential, PVSys.
SESSION 3A: a-Si and c-Si Thin Film Technologies, ALADAĞ HALL
Polycrystalline Si Thin-Film Solar Cells on Glass – Challenges and Opportunities
Prof. Stefan Gall, [email protected]
Helmholtz-Zentrum Berlin für Materialien und Energie, Institute for Silicon Photovoltaics, Germany
Wafer-based crystalline Si solar cells are still dominating the PV market. The reduction of the Si thickness is an appealing way to
bring down costs because even relatively thin crystalline Si solar cells feature the potential for high efficiencies. But in order to
bring down costs substantially high efficiencies have to be reached with a real Si thin-film technology utilizing production
techniques for large-area low-cost foreign substrates (e.g. glass). The Si thin-film solar cells on glass available in the market
today are based on hydrogenated amorphous Si (a-Si:H) and hydrogenated microcrystalline Si (µc-Si:H). Unfortunately, both
materials probably do not have the potential for very high efficiencies because the structural quality is relatively poor. Therefore
Si layers with higher material quality are required. High quality polycrystalline Si (poly-Si) thin films on glass feature the potential
to reach high efficiencies at low costs. However, the preparation of these poly-Si films poses a big challenge because the glass
substrate limits the process temperatures to about 600°C. Usually the preparation is based on a two-step process. In the first
step an amorphous Si (a-Si) film is deposited and in the second step this a-Si film is crystallized. For example, the a-Si layer can
be crystallized by a simple annealing step lasting several hours at about 600°C (solid phase crystallization - SPC). So far, minimodule efficiencies of up to 10.4% (on 94cm2) have been reached with this approach. In the first part of this talk the state of the
art of SPC-based poly-Si thin-film solar cells is reviewed and in the second part the main challenges for the existing poly-Si
technology and the related opportunities are discussed. This discussion includes both approaches which should result in
significant cost reductions and approaches which should result in significant efficiency improvements. Based on the approaches
discussed in this talk, the production of low-cost poly-Si thin-film solar cells on glass with efficiencies significantly above the
current record should be feasible.
34
Fabrication and Doping Thin Film Crystalline Si by Electron Beam Evaporation for Solar Cell
Applications
M. Karaman, S. H. Sedani, K. Ertürk,, R. Turan,
Atılım University, Physics Group, Turkey
Faculty of Arts and Sciences, Department of Physics, Namık Kemal University, Turkey
The Center for Solar Energy Research and Applications and Department of Physics, Middle East Technical
University, Turkey
Thin film crystalline silicon on glass and amorphous silicon have great emphasis for photovoltaic applications due to having an
easy production and being cost effective with respect to crystalline silicon. Electron beam technique as a Physical Vapor
Deposition (PVD), is attractive due to having a non-toxic environment and easy production facility. In this study the doping
analysis and electrical properties of amorphous and polycrystalline silicon thin films were investigated. Amorphous silicon was
deposited by e-beam method and in-situ doping of phosphorus and boron were supplied by effusion cells. Evaporation
temperature for boron and phosphorus, 1800 °C and 700 °C were used. The doping of the amorphous silicon films was
optimized by using different silicon evaporation rates which effects the concentration of dopants. Three different evaporation
rates of 10-20-50 Å/s were used. Hall effect measurements were accomplished to analyze the active dopant amount and dark
current-voltage measurements were done to find out the resistivity of the amorphous silicon films. Then the films were
crystallized by classical furnace annealing at 600 °C for more than 20 hours and exposed to rapid thermal annealing (RTA) at 900
°C for 4 minutes. After that the films were hydrogenated to saturate the dangling bonds between the grains. The crystallinity of
the films were confirmed by Raman Spectroscopy and the dopant profile was revealed by Secondary Ion Mass Spectroscopy
(SIMS) . Hall effect and current-voltage measurements were also carried out to analyze the electronic properties of the films
after crystallization and hydrogenation process. All of the steps were performed both for boron and phosphorus doped samples.
Simulation Studies on Hydrogenated Amorphous Silicon Solar Cells
Prof. Aynur Eray, MSc. Melis Bilgiç Aksarı, Dr. Giuseppe Nobile, [email protected],
Hacettepe University, Faculty of Engineering, Department of Physics Eng., 06800 Beytepe, Ankara, TURKEY
In order to improve the conversion efficiency and stability of the hydrogenated amorphous silicon (a-Si:H) solar cells, it is
important to analyze their output characteristics and to optimize the conditions under which they are manufactured. Since
computer models are an excellent tool for studying transport mechanism and also as a method that can lead to a better device
design, amorphous silicon alloy device modeling has been receiving a great deal of attention in the last 20 years. In the
literature, there are several computer programs for modeling amorphous silicon solar cells. Therefore in this study, a detailed
simulation studies of I-V characterization of single junction p–i–n amorphous silicon solar cells and a-Si:H/c-Si heterojunction
solar cells have been presented, in order to get more insight into the factors determining the solar cell performance. AMPS-1D
(Analysis of Microelectronic and photonic structure) device simulation program has been used to present data concerning the
optimization of electronic properties of amorphous silicon p-i-n solar cells and examines the correlation of the external electrical
characteristics to the internal solar cell properties such as band diagram, the electric field profile, free and trapped carrier
concentrations, space charge density, recombination rate profiles, electron and hole lifetime and spectral response. The
simulation program and its application were extensively described. Applying an optimized graded buffer layer at p+/i interface
of single cell, a further efficiency improvement has been realized. A standard procedure of mid gap density of state optimization
of p+ window layer and p+/i buffer layer has been performed. We have investigated the degradation kinetics of a-Si:H solar cells
with improved buffer design. The influence of the mid gap defect density and the thickness variations in the intrinsic layer were
also studied to improve the stability. Our findings show that thin cells can be exposed to light for longer periods before
degradation effect dominates their operation. Stability can be improved by reducing the thickness of the intrinsic layer. The
design and optimization of a-S:H /c-Si heterojunction solar cell was done with AFORS-HET (Automat FOR Simulation of
HETerostructures) simulation program. Detailed simulation studies of I-V characterization of heterojunction solar cells have
been carried out with TCO/ (n) a-Si:H/ (i) a-Si:H/ (p) c-Si/BSF/Ag structure. The effect of a-Si:H (i) layer, at a-Si:H/c-Si heterointerface, on the cell performance was investigated in details. It is also investigated the influence of the thickness of all layers,
different defect configurations and defect concentration in c-Si (p) and the change of mobility gap for (p++) a-Si:H BSF layer.
Morover, the interface defects at the front and back side of the c-Si (p) absorber is also considered. The results of these
simulation studies have been seen to be good agreement with the reported studies in the literature. 1. A. Eray, G. Nobile,
Recent Developments in Solar Energy, Editor: Tom P. Hough, 2007 2. Melis Bilgic Aksari, Aynur Eray, Energy Procedia, Volume
10, p. 101-105, 2011. 3. M. Bilgic Aksari, A. Eray, Proceedings of the 26th EU PVSEC, p 1497-1502, 2011. 4. A. Eray, G. Nobile,
Proceedings of the 26th EU PVSEC, p 2519-2524. 2011.
35
Recombination mechanisms in low impedance hydrogenated silicon nano-crystalline thin
films
Assoc. Prof. Dr. Zaki Saleh, Ms. Salam Kmail, Ms. Samah Assaf, Prof.Dr. Atef Qasrawi, [email protected],
Arab American University-Jenin Department of Physics Arab American University-Jenin P.O. Box 240, Jenin,
Palestine
The photoconductivity dependences on temperature and illumination intensity was investigated for low-impedance
thin films of hydrogenated nano-crystalline silicon (nc-Si:H) grown by very high frequency, plasma enhanced
chemical vapor deposition (PECVD). The nanocrystalline phase was achieved by heavy hydrogen dilution of silane
(SiH4) during growth. We find that the activation energy of the photoconductivity is sensitive to the incident
illumination intensity for illumination intensities below 40 klux. The photocurrent follows a power-law dependence
on illumination intensity (Iph ~ F ^γ), with γ ranging from 0.36 to 0.83. The illumination dependence of the
photocurrent suggests two different recombination mechanisms depending on temperature. In the lower
temperature regime (300 – 340 K), recombination appears to be dominated by a linear (monomolecular) process
while at higher temperatures (350 – 400 K), it is likely dominated by a sublinear (bimolecular) process.
Keywords: Photoconductivity, photovoltaics, solar cell, nano-structure, silicon, recombination
Laser ablated nanocrystalline Silicon thin film for solar cell application
Assoc. Prof. Dr. Fawzy Mahmoud, Dr. Mostafa Boshta, [email protected],
National research center-Egypt
Solid State Physics Dept., National Research Center, P.O. 12311, Dokki, Giza, Egypt In this paper thin films of
nanocrystalline silicon on glass substrate have been prepared by with femtosecond laser ablation of High purity
(>99.99%) Si target at different substrate temperature. The structural properties and morphology of thin film were
characterized by XRD, UV–Visible-NIR spectrophotometer, transmission electron microscopy, Fourier transform
infrared spectroscopy, and atomic force microscopy. XRD data of Si thin film prepared at different substrate
temperatures shows that our films is nanocrystalline materials and the crystallinity increase with increasing the
deposition temperature. The electrical conductivity data showed that the conductivity of our films is in line with
XRD data where it increases with increasing the deposition temperature
Keywords: nanocrystalline silicon, thin film, laser ablation
36
Efficiency enhancement of a-Si:H single junction solar cells by the incorporation of metallic
nanodots or a-Ge:H at the p+ a-SiC:H/transparent conducting oxide interface
Assoc. Prof. Dr. Ahmed Abou-Kandil, Dr. Jeehwan Kim Dr. Devendra K. Sadana, [email protected],
Egypt nanotechnology Center Building 121 Smart Village. Cairo -Alexandria Desert Road. Egypt 12577
Addition of carbon into p-type “window” layers in hydrogenated amorphous silicon (a-Si:H) solar cells enhances
short circuit currents and open circuit voltages by a great deal. However, a-Si:H solar cells with high carbon-doped
“window” layers exhibit poor fill factors due to a Schottky barrier-like impedance at the interface between a-SiC:H
windows and transparent conducting oxides (TCO), although they show maximized short circuit currents and open
circuit voltages. The impedance is caused by an increasing mismatch between the work function of TCO and that of
p-type a-SiC:H. Applying ultrathin high-work-function metals at the interface between the TCO and the p+ layer
results in effective lowering of the work function mismatch and a consequent ohmic behavior. If the metal layer is
sufficiently thin, then it forms nanodots rather than a continuous layer which provides also light scattering effect.
We demonstrate 31% efficiency enhancement by using high-work-function materials for engineering the work
function at the key interfaces to raise fill factors as well as photocurrents. Another method that increases the C
incorporation in p+ a-SiC:H but without adversely affecting the FF, is by adding a thin layer of hydrogenated
amorphous germanium (a-Ge:H) buffer at the pþ a-SiC:H/ TCO interface. The presence of a-Ge:H can either
minimize or eliminate the Schottky barrier. We also demonstrate more than 25% enhanced efficiency of the a-Si:H
solar cell by using the a-Ge:H interfacial buffer compared to that without an a-Ge:H interfacial layer.
Keywords: amorphous Silicon; PV; ZnO; p+ interface
SESSION 3B: Operation and Performance, TOROS 1 HALL
Photovoltaic Solar Power Plant Design Criteria and System Reliability
Harun Girgin, [email protected]
Anel Enerji, Turkey
Solar photovoltaic technology, with its relatively faster installation figures, lack of a need for fuel and ease
of operation and maintenance, is becoming a popular source of energy generation in response to Earth’s
rapidly increasing energy needs.
Although solar power plants are simpler in structural terms, significant experience in engineering is
required for their design, installation and operation. This necessitates an all-encompassing approach by
seasoned engineers from all relevant fields for the design of any solar power plant. While each kWh
produced from the operation of the power plant provides shorter terms on return of investment to the
undertaker, the slightest mistakes in design may lead to dramatic increases in said terms due to drops in
efficiency or halts in operation of the power plant.
Even though the location of the solar power plant project plays an important role in design, the structure
of the high voltage line for system connection, the telecommunication infrastructure of the area,
meteorological data encompassing long intervals, geological structure and the state of security of site play
equally important roles. Thus said, employing engineers from the fields of electronics, construction,
mechanics, geology, automation and computer software would increase the performance and efficiency of
any solar power plant.
The following work states the design criteria of a solar power plant and the necessary steps in providing
system reliability.
Keywords: Sun, photovoltaic, solar power plant, design, system reliability
37
Operation and Performance of Grid Connected Solar Photovoltaic Power System in Kocaeli
University
Assoc. Prof. Dr. Engin Özdemir, Master Student Ahmet Aktaş, MSc. Abdulhakim Karakaya Dr. Mehmet
Uçar, [email protected],
Kocaeli University Faculty of Technology Department of Energy Technology Umuttepe 41380 Kocaeli
In this study, operation and performance of grid-connected solar photovoltaic (PV) power system in Kocaeli
University are explained. The grid-connected PV power system consists of 720 Wp thin-film PV panels, 1 kW gridconnected inverter and a WebBox for internet connection. The PV system has been installed first 360 Wp in March
2010 and upgraded for 720 Wp in August 2011. Each PV panel has a power of 60 Wp Kaneka thin-film modules are
installed in the PV system. The SMA Sunny Boy 1 kW grid-connected inverter is connected to perform the
conversion of the direct current generated by the PV panels into mains standard alternating current and also
adjustment of the inverter's operating point to the MPP of the PV panels (MPP tracking) in order to feed the
maximum power into the electricity grid. The power, voltage and current harmonic values at grid side of the
inverter have been measured using Fluke 434 power quality analyzer. After March 2012, the PV system has internet
connection via SMA Sunny WebBox. The produced PV electric energy amount can be monitored in our department
website (enerji.kocaeli.edu.tr) in hourly, daily and monthly basis. The obtained data and measurement records will
be given in the full text paper for showing the performance of grid-connected PV power system.
Keywords: Grid-connected power system, inverter, photovoltaic (PV), solar energy
An Off Grid Photovoltaic System Design for Fish Cages in Farms
Dr. Gökay Bayrak, Fishery Engineer, Ali
Prof.Dr. Mehmet Cebeci, [email protected],
Atilla
Uslu,
Gürel
Nedim
Örnekçi,
Gökhan
Karakaya,
Firat University Electrical and Electronics Engineering Department Elazig/TURKEY
Solar energy is clean, renewable and plentiful in the nature and the energy needs and costs have increased in
recent years. These conditions have made solar energy more important. On the other hand, due to rapidly
developing photovoltaic (PV) technology, PV based applications have been developed recently. Off-grid PV systems
have been used in many applications just like remote dwellings, electric cars, remote sensing and protection of
pipelines. Also there are some applications in power stations, in buildings, in transport, in rural electrification and
solar roadways. In this application study, an off grid PV system designed for fish cages stand on Keban Dam Lake in
Elazig/Turkey. An off grid PV system designed to supply the systems’ required electrical energy and a pump used
for taking cold water from the depth of the dam lake to cool the cage. All the energy requirement of the system is
supplied from designed PV system. For this purpose, An off grid PV array consists of 8 PV panels which have each
one 205 Wp, 32.47 V open circuit voltage and 8.39 A short circuit current technical specifications was designed.
Developed PV array was constructed on the fish cage to supply the system’s required electrical energy.In studied
system 2 charge controller were used which have 30 A maximum current to control the charge and switching
between PV array and batteries.Also, 2200 W, 24 V DC input voltage and 230 V AC output voltage sine wave
inverter was used in this project. Providing sufficient power is supplied from 8 batteries have 12 V, 110 Ah. All
design parameters and design steps was explained in this paper. Thanks to developed system, the temperature of
fish cage is stabilized to appropriate temperature so from May to September fish can be growth sustainably during
the year.
Keywords: Photovoltaic System Design, Off Grid, PV, Fish Farms
38
Investigation of Performance For Fixed-Inclined, One Axis and Two-Axis Tracking Photovoltaic
System in Different Parts of Turkey
Bedrettin Uzun, Gülin Acarol Zilanlı, Ömer Akan, Prof.Dr. Aynur Eray, [email protected],
Hacettepe Üniversitesi Beytepe Kampüsü Yeni ve Temiz Enerji Araştırma Uygulama Merkezi (YETAM) Güneş Evi
Beytepe/ANKARA
Investigation of Performance For Fixed-Inclined, One Axis and Two-Axis Tracking Photovoltaic System in Different
Parts of Turkey Bedrettin Uzun1, Ömer Akan1. Gülin Acarol Zilanlı1, Aynur ERAY1, 2 1Hacettepe University, New
and Clean Energy Research-Application Center, Beytepe, Ankara 2Hacettepe University, Department of Physics
Eng., 06800 Beytepe, Ankara In this study, SolarGIS-pvPlanner simulation tool has been used to investigate the
performance for fixed-inclined, one axis and two-axis tracking photovoltaic systems in different regions of Turkey.
The influence of PV module technology have also been studied in detail. pvPlanner is a simulation tool for planning
and optimisation of photovoltaic systems using climate and geographic data at high temporal and spatial resolution
and new generation high performance algorithms. In this tool, photovoltaic power production is simulated using
numerical models developed or implemented by GeoModel using aggregated data based on 15-minute time series
of solar radiation and air temperature data as inputs. In estimation of the PV production considered in pvPlanner, it
is assumed start-up phase of a PV project, and long-term degradation of PV modules is not considered. During
modelling studies, it has been choosen 10kW photovoltaic power plant with different module technologies
including single crystalline silicon (c-Si), amorphous silicon (a-Si) and copper indium selenide (CIS) in different sites
of Turkey. The sites’ elevations were choosen above 1000 meters. Site parameters such as solar radiation
parameters, air temperature parameters, terrain characteristics are provided by solargis database. For technical
parameters such as the inverter euro efficiency and dc/ac losses parameters, the default values of 97.5% and
5.5/1.5 were taken into consideration respectively, as given in the simulation tool. Our simulation results show
that, although there is a high pv electricity production in the southern part of Turkey, the gain for two axis tracking
is increasing for middle and northern parts of Turkey. The highest energy yield can obtained by using a two-axis
tracking system, and the energy gain over the year is between 23% and 46% depending on the lattitude of the
selected cities and PV module technologies. Performance ratios of 10kW PV solar system with the PV modules of
single crystalline silicon, thin film amorphous crystalline silicon and CIS has been evaluated as 0.81, 0.82, 0.82
respectively. The results have been explanined and discussed in detail with the existing experimental data in the
literature.
Keywords: pvPlanner, PV power plants, modeling
Circuit-based simulation model for photovoltaic panel
Dr. Mustafa Engin, [email protected],
Ege University Ege MYO Electronics Technology Bornova, 35100, Izmir, Turkey
In this paper, a circuit-based simulation model for photovoltaic (PV) panel is developed. The method is used to
obtain the parameters of the panel model using information from the datasheet. Developed model is suitable for
use with power electronic converters in dynamic and transient power system simulation. For power system level
studies, existing models have unnecessary complexities and implementation difficulties in various software tools.
The proposed model is simple and implementation is straightforward. The photovoltaic panel model can be
simulated with any circuit simulator. it can even be constructed using standard software library components as
demonstrated in this paper using Simulink simpower toolset. Compared to energy based PV models, the model’s
circuit-based nature enables the electrical engineer to better visualize and understand the PV device and its
behavior in the connected circuit. The proposed model can be applied to any brand of PV modules by setting the
parameters properly. The equations of the model are presented in details and the model is validated with
experimental data.
Keywords: photovoltaics, photovoltaic power systems, PV panel modeling, circuit-based PV cell model
39
Partially Shaded Characterization Effect On Two Different Single Crystalline Photovoltaic
Modules With Bypass Diode
MSc. Gencer Sarıoğlu, Dr. Rustu EKE, [email protected],
Mugla Sıtkı Kocman University, Faculty of Sciences, Department of Physics
One of the main causes of losses in energy generation within photovoltaic (PV) systems is the partial shading on
photovoltaic modules. A PV system can easily lose a significant portion of its total output with only minimal
shading. A bypass diode in the module will form an alternating path for the current generated from the unshaded
parts and prevent these cells/modules from damage in the array. Because solar cells are not designed to support a
reverse voltage, they may be degraded, depending on the applied voltage. Virtually all modern PV modules include
bypass diodes. The purpose of this work is the study of power decrease of two single crystalline silicon photovoltaic
modules with different rated powers under varying shading. The shading is applied from east to west, west to north
and south to north. The current voltage curves are analyzed for each shading to define the power decrease in
detail.
Keywords: shading effect, photovoltaic modules, crystalline silicon, bypass diode
SESSION 4A: New Materials and Concepts, ALADAĞ HALL
The German-Turkish project RainbowEnergy: A Si-based nanocomposite absorber for thin film
PV cells
Karl-Heinz Heinig, Atilla Aydinli, Rasit Turan, Dirk Hauschild
Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
Bilkent University, Physics Department, 06800 Bilkent, Ankara, Turkey
Department of Physics, Middle East Technical University, Ankara, Turkey
LIMO Mikrooptik GmbH, Bookenburgweg 4-8, 44319 Dortmund, Germany
Si-based thin film PV cells suffer from a rather low efficiency. This leads to a relative small market share, although
their module prices are comparably low. RainbowEnergy aims at a novel nanostructured Si-based thin film PV cell
absorber, which increases the efficiency substantially without increasing the module costs.
Large-scale patterning by spontaneous self-structuring during spinodal decomposition of metastable SiO is a
promising synthesis process of nanostructured Si absorbers for 3rd generation thin-film solar cells. The SiO layers
have been produced by different techniques, sputtering, CVD and e-beam evaporation. Spinodal decomposition has
been activated by Rapid Thermal Processing (RTP, several seconds), very Rapid Thermal Processing (vRTP, dwell
time tens of msec), and laser annealing.
If after phase separation SiOx  0.5SiO2 + (1-0.5x)Si the volume fraction of Si exceeds ~30%, then Si forms a
percolated nanowire network. Energy-Filtered Transmission Electron Microscopy (EFTEM) studies show that
nanowires have diameters of a few nanometers with a narrow distribution. This is in excellent agreement with
large-scale simulations based on kinetic Monte-Carlo.
As the wire diameters coarsens with time of heat treatment like d~t1/3, and because the Si bandgap opens for nmstructures by quantum confinement, a band gap engineering for PV cell optimization becomes feasible. It will be
shown that up-scaling of the nanotechnology described above to large-scale PV cell production is under way with
industrial partners
40
Spectroscopic Ellipsometry Studies
Characterization of Crystallization
of
nc-Si/a-Si
and
nc-Si/SiO x
Systems:
Optical
Gizem Nogay, Serim İlday, Prof. Raşit Turan, Prof. Karl Heinz Heinig, David Friedrich, [email protected]
GÜNAM, Middle East Technical University, TURKEY, **HZDR, GERMANY,
Third generation solar cells are expected to utilize the quantum size effect occurring in the semiconductor quantum
dots fabricated in an appropriate matrix. A promising and well-studied material system is the Si nanocrystals
fabricated in an oxide matrix such as SiO2. In spite of extensive research efforts on this material system, a
successful device realization has not been possible due to the difficulties in the device fabrication and the
electronic transport in the dielectric matrix that forms an insulating medium for the charge transport. In order to
overcome the problems related to the electronic transport while not losing the quantum size effect, the use of a
sponge-like nanostructure has recently been proposed. Si nanosponge is composed of tiny interconnected Si
nanostructures embedded in an oxide matrix. These nanostructures form an interconnected quantum structure
where the charge transport does not require the tunneling current which needs well positioned quantum dots. The
band gap of the material can still be engineered by process parameters for tandem solar cell fabrication. Sinanosponge is then a promising candidate for the fabrication of third generation photovoltaic (PV) solar cells. In
this work, Si-nanosponge structures were fabricated successfully in a SiOx matrix in a wide range of x values
(0<x<2). The effect of DC power applied to the Si target and annealing condition is investigated. Photoluminescence
(PL) analysis shows that the quantum confinement effect is active for the low DC powers. A blueshift observed in PL
data when the applied DC-power is reduced, which correlates with a decrease in average nanocrystal size. X-ray
photoelectron spectroscopy shows that the Si-nanosponge structure is distributed evenly throughout the film. We
also report on optical characterization and spectroscopic ellipsometry studies of nc-Si/SiOx systems in search for a
methodology to better understand the relation between optical properties and volume fractions of existing
subspecies in these systems. This way we try to produce every possible subspecies in an nc-Si/SiOx system and we
show that different combination of these material systems could be analyzed with the same approach. Substoichiometric species fractions are verified with x-ray photoelectron spectroscopy analysis. We use Tauc-Lorentz
and Bruggeman effective medium approximation models in order to extract the optical properties of the system.
We find that these parameters are highly depending on x-value, hence on nanocrystal size, and the fraction of
existing components in the system. High-resolution transmission electron microscopy (HR-TEM) and energy filtered
transmission electron microscopy (EF-TEM) results are also very correlated with the structure that is used for
optical fitting of the spectroscopic ellipsometry measurement.
41
Carbon Nanostructures as Transparent Electrode for Thin Film Solar Cells
Dr. Mostafa El-Ashry, Dr. Osama Tobail, [email protected],
Egypt Nanotechnology Center (EGNC) Smart Village, Building B121 Cairo-Alex Desert Rd. Km. 28, P.O. 12577
Current thin film solar cell technology utilizes transparent conductive oxides such as Indium Tin Oxide (ITO) and,
more recently, Aluminum doped Zinc Oxide (ZnO:Al). These materials suffer fundamental drawbacks in their
processing as expensive vacuum deposition techniques are necessary. That is in addition to its inability to satisfy
the requirements for flexible applications. Also, the vacuum deposition process is not suitable for forming patterns
on the surface, which results in the need of expensive photo-lithography processing. Due to these drawbacks, an
alternative material is required. Carbon nanotubes are seen as a promising substitute material. In this contribution,
we emphasize on our efforts of synthesizing single wall carbon nanotube (SWCNT) based TCE and integrating it with
amorphous silicon thin film solar cells. Different sources of nanotubes were examined to optimize film
performance. In addition, a new stable dopant for the CNT, unlike the standard conventional unstable nitric acid
dopant, is introduced. A sheet resistance of 6 ohm per square at transparency of 85 % was achieved. The optoelectric performance of such SWCNT based TCE is comparable to the current available technologies, beside the
advantageous of being cheap solution based process, low material cost and compatibility with flexible substrates.
The produced CNT based TCE is integrated to thin film amorphous silicon solar cells as a front transparent
electrode. The first working cell with the new TCE is presented.
Keywords: Transparent conductive electrode, thin film solar cells, carbon nanotubes
Structural, Optical and Electrical Properties of Zinc Oxide and Aluminum Doped Zinc Oxide for
Photovoltaic Applications
MSc. Nilüfer Evcimen Duygulu, Assoc. Prof. Dr. Alp Osman Kodolbaş Dr. Özgür Duygulu, Prof. Dr. Ahmet
Ekerim, [email protected],
Yıldız Technical University, Faculty of Chemistry and Metallurgy, Department of Metallurgy and Material
Engineering, Esenler, İstanbul
Zinc Oxide (ZnO) and Aluminum doped ZnO thin films (ZnO:Al) were deposited on glass substrate by R.F. magnetron
sputtering by varying target-substrate distance, RF power and gas flow rate. Structural, electrical, optical properties
of the films were investigated using XRD, SEM, AFM, HRTEM, four point probe, optical transmission measurements.
The XRD and HRTEM measurements revealed that all of the obtained films were preferentially polycrystalline with
the hexagonal structure and had a preferred orientation with the c-axis perpendicular to the substrate. High quality
films with the resistivity as low as 1 × 10− 3 Ω-cm and transmittance over 75% for ZnO films and 6 × 10− 4 Ω-cm and
transmittance over 85% for have been for ZnO:Al obtained by suitably controlling deposition parameters.
Developed ZnO:Al films were used as transparent front contact of a-Si:H/c-Si heterojunction solar cells. We have
achieved 9.2% efficiency on 100mm diameter c-Si wafers.
Keywords: ZnO, ZnO:Al, RF magnetron sputtering.
42
Single Crystal Growth of Germanium – Silicon Alloys
Ercan Balıkçı, Aidin Dario, Hasan Özgen Sicim, [email protected]
Department of Mechanical Engineering, Boğazici University, Bebek 34342 Istanbul – Turkey,
Germanium-silicon (Ge–Si) alloys enjoy a widespread interest because of their remarkable potential for
optoelectronic, solar cell, thermoelectric power generation, and photodetector applications. Despite this obvious
interest, Ge-Si crystal growth has difficulties. Ge-Si alloy system is extremely prone to segregation due to its
thermo-physical properties. This prevents the growth of quality bulk crystals of Ge-Si, which are the basis for
example for solar cells as wafers. A new bulk crystal growth technique called axial heat processing (AHP) is
proposed to alleviate the adversities during Ge-Si single crystals. The technique makes use of an immersed baffle
that spreads the heat over the growth interface, decreases the melt height, and divides melt into two regions.
Several silicon doped germanium single crystals with 5 and 12 atomic percent concentration have been grown by
the AHP method at 0.75 mm/h and 2 mm/h velocity with two different melt heights. Few Bridgman crystals have
also been grown to set a base for a comparison between the crystals grown by the AHP and Bridgman techniques.
The effect of the processing variables on the longitudinal and radial dopant distribution and single crystal quality is
investigated. A new theoretical approach is also proposed to predict the solute redistribution and morphological
stability in the grown crystals. The predictions of this new model are found to be superior when compared to those
of Constitutional Supercooling (CS) and Mullins and Sekerka (MS) criteria.
Keywords: Single crystal growth, Ge-Si, AHP, Bridgman
Near Field Radiative Transfer: A Review
Prof. M. Pinar Mengüç, [email protected]
Center for Energy, Environment and Economy and School of Engineering, Özyegin University, Turkey
Detailed theoretical and computational studies and carefully conducted experiments of radiation transfer are
needed for future developments of nano-scale energy harvesting devices, manufacturing processes that function at
nano-scales, and measurement techniques with nano-scale resolutions. These studies would allow us to
understand the physics between objects at close proximity to each other. This understanding then can be used to
engineer new devices and processes. Only during the last decade the importance of near field radiation has gained
recognition because of its potential to impact the advances in nanotechnology and nano-scale patterning
processes.
During the last decade, theoretical framework and numerical methodologies for near-field radiation transfer
simulations have been studied by different groups, including ours. The Maxwell electromagnetic wave equations
are always used for this purpose; however, their solution for near-field radiative transfer requires additional
constitutive relations and formulations in order to describe absorption, scattering and emission mechanisms with
plasmonic effects. It is important to realize here that the Maxwell equations describe the propagation of
electromagnetic waves and scattering phenomena. They do not account for the physics behind emission and
therefore by themselves they are not sufficient to understand the near-field radiation transfer. The simulations of
these processes need to start with the Maxwell equations coupled with the fluctuational electrodynamics
formalism, where the source of thermal radiation is to be modeled as a stochastic current density. The
monochromatic radiative flux in a film is then determined by calculating the time-averaged the Poynting vector and
by applying the fluctuation dissipation theorem. On the other hand, the measurements of near-field radiation
transfer have become possible only recently with the availability of tools developed with the advances on
nanotechnology and with the developments of nano- and micro-tools.
In this presentation, different methodologies are first outlined for the solution of the near-field radiative transfer.
In addition, a general review of the experiments for the measurement of near-field radiation transfer will be
provided. The current state-of-the art and the shortcomings of both the theoretical and experimental studies will
be outlined.
43
SESSION 4B: Markets for Solar Electricity Systems, TOROS 1 HALL
Anayzing Applicability of Solar Power Usage with State Support in Buildings
Lütfü Sagbansua, [email protected], Vedat Kıray, [email protected]
PhD, Department of Business Administration, School of Economics and Administrative Sciences, Turgut Ozal
University, Ankara, Turkey.
PhD, Department of Electronics, School of Engineering, Turgut Ozal University, Ankara, Turkey.
Electricity consumption reaches its peak between 19:00 and 22:00 worldwide and this consumption occurs largely
in the residential areas. The isolated houses have advantages in terms of applicability of solar panels while the
same oppotunity does not exist for apartment complexes. Having many flats and not enough space for the
installation of solar panels, tenants of such complexes are not able to act independently. However, usage of solar
energy has vital importance for energy productivity, consumption control, and supporting the production especially
for countries like Turkey where the majority of the population lives in apartment complexes. For instance, while the
energy consumption in a complex with 50 flats means 50 times more than the consumption of isolated houses, the
ability of the same complexes to produce its own energy means a great gain. The main barriers of the solar panel
usage in the apartment complexes are the requirement of the common usage of panels which requires the flat
owners act together, and unbalance between the number of flats and roof space. These problems mentioned
require not only solution for the technical hardware but also economic solution as well. This study at hand presents
a solution to the issue from the economic perspective. It is aimed to minimize the necessity of flat owners acting
together by developing a scenario of not reflecting the set up cost to the owners. On the other hand, the set up and
its cost are left for the private companies to handle. It is estimated that the set up cost along with a profit equal to
the average interest rates to be paid by the flat owners to the companies seting up the system in 20 years which is
the average lifetime of the panels. The resulting scenario shows that the amount of monthly payments of the
owners to the company throughout the 20 years are nearly 30 % lower that their monthly electricity and gas
payments. It is also presented how the State support discussed in the research pays back in various ways along with
the economic activity estimated in the solar panel market. An apartment complex with 20 flats in 5 floors are
chosen for the illustration purposes in the final section.
Keywords: Smart grids, microgrid, micro smart grids, solar energy, investment anaysis.
Customized Technological Solutions for Rural Electrification Based on Renewables
Hakkı Karacaoğlan*, Michael Wollny, [email protected]
*SMA Solar Technology, GERMANY
What are the possibilities if we need immediate access to reliable electricity at any time to increase the economic
productivity?
Extension of the distribution grid is cost intensive and often not economical because of the low consumption in this
area.
Renewables allow a better use of local natural sources.
44
Clean energies development and built environment
Dr. Abdeen Omer, [email protected],
Energy Research Institute (ERI) Nottingham NG7 4EU United Kingdom
There is strong scientific evidence that the average temperature of the earth’s surface is rising. This is a result of
the increased concentration of carbon dioxide and other GHGs in the atmosphere as released by burning fossil
fuels. This global warming will eventually lead to substantial changes in the world’s climate, which will, in turn, have
a major impact on human life and the built environment. Therefore, effort has to be made to reduce fossil energy
use and to promote green energy, particularly in the building sector. Energy use reductions can be achieved by
minimising the energy demand, rational energy use, recovering heat and the use of more green energy. This study
was a step towards achieving this goal. The move towards a de–carbonised world, driven partly by climate science
and partly by the business opportunities it offers, will need the promotion of environmentally friendly alternatives,
if an acceptable stabilisation level of atmospheric carbon dioxide is to be achieved. This requires the harnessing and
use of natural resources that produce no air pollution or greenhouse gases and provides comfortable coexistence
of human, livestock, and plants. This article presents a comprehensive review of energy sources, the development
of sustainable technologies to explore these energy sources. It also includes potential renewable energy
technologies, energy efficiency systems, energy savings techniques and other mitigation measures necessary to
reduce climate change. The article concludes with the technical status of the ground source heat pumps (GSHP)
technologies.
Keywords: Green energies, energy efficiency, sustainable development, built environment
A Smart Grid Approach Energy Management with Social Media
Melih Ballıkaya, MSc. Michael Bez, MSc. Ozan Özışık, [email protected],
Yıldız Teknik Üniversitesi, A.I.B.U. Teknopark No:2 Bolu Türkiye
With the development of technology and the increasing level of prosperity, electrical energy demand generally
increases. The consumption of electrical energy per capita in Turkey is estimated to be about 5000kWh/a in
2023[EIE]. The corresponding population of Turkey and the total electricity demand are expected be 88.24 million
people and 411.2 TWh (TUIK). With a share of 45,5% of the total electricity consumption households and offices
will play big role in the energy system of Turkey. As a major prerequisite, intelligent management of load between
energy generation and consumption requires smart grid solutions. Also the developing sector of renewable
energies forces electricity suppliers to think about new and intelligent ways to assure a constant equilibrium
between supply and demand. Therefore demand-management in houses and offices can be seen as a quick and
cheap way to balance energy production and consumption.
Keywords: Smart Grid, Home Area Network, Energy Management
45
PV Investment Project Development Stages in Turkey
MSc. Deniz Selkan Polatkan, [email protected],
Motif Proje, Halide Nusret Zorlutuna Sok 11-1 Çankaya Ankara
Turkish pv market has just started and we have to care about to develop with the right, sustainable, trustfull and
example pv projects in our market. New actors in the power market can begin operating with a new bottom-up
control logic. Unsubsidised PV markets may start to take off in 2013, where PV power is getting cheaper than grid
electricity prices. Managing this new trend and choice may be a new beginning for the energy independancy and
energy autonomy. .This consumption—production balance may trigger massive innovation and investment in
energy management technologies involving different kinds of storage and controls. Increasing autonomy and
flexibility of consumers challenges the top-down control logic of traditional power supply and pushes for a more
decentralised and multi-layered system. How rapidly and smoothly this transformation occurs depends to a large
extent on the adaptation speed of the regulatory framework and on the ability of market players to develop
appropriate business models. Unlicenced pv projects will be the key development on that way, and the most
important starting steps are; 1- where to put the modules, on the land or on the lost places such as landfills ? 2how to choose the grid connection ? 3- is the infrastructure available and enough to build pv generations ? 3- how
to manage the environmental risks on pv such as dust or shading. 4- what to care on the land use planning for site
selection for pv 5- how to manage all these steps ? The paper discusses conflicts of interest; hurdles and drivers;
opportunities; and traps for this perspective.
Keywords: pv -market-ınvestment-development-project
SESSION 5A: CdTe/CdS and CIGS, ALADAĞ HALL
CdTe solar cells in substrate configuration
Dr. Julian Perrenoud, Lukas Kranz, Rafael Schmitt, Julian Perrenoud, Christina Gretener, Fabian Pianezzi, Stephan
Buecheler, Ayodhya N. Tiwari
Laboratory for Thin Films and Photovoltaics, Empa – Swiss Federal Laboratories for Material Science and
Technology, Switzerland
CdTe solar cells are conventionally grown in superstrate configuration on glass substrates and flexible solar cells on
polyimide films have also been developed in this configuration. However, the processing of CdTe solar cells in an
inverted structure, the so called substrate configuration, offers numerous advantages, including the possibility of
choosing a variety of substrate materials including metal foils. Substrate configuration offers better control of
junction properties as recrystallization of CdTe and the CdS-CdTe heterojunction junction formation can be
decoupled. On the other hand, several challenges, especially stability of electrical back contact has to be overcome
for achieving high efficiencies. Recently, some research groups are revisiting the substrate configuration concept
for CdTe solar cells and have initiated research and development work. Using a low temperature evaporation
process our group has achieved high efficiency solar cells on glass as well as on metal foils. Progress in the
development of flexible CdTe solar cells will be presented.
46
Current state and future prospects of thin film solar cells
Prof. HANS-WERNER SCHOCK, Helmholtz Zentrum Berlin für Materialien und Energie, Germany
[email protected]
The growth of PV installations exceeds all earlier expectations. Installations of photovoltaic systems cumulate to
more than 100 GW worldwide in 2012. Thin film solar cells were expected to take a major share of the market
because of their intrinsic advantages for high volume manufacturing. Thin film solar module in particular CdTe and
CIGS based modules reach high efficiencies approaching the performance of multicrystalline silicon. Nevertheless,
wafer based silicon modules dominate the market. In this presentation the status of thin film solar cell
development and prospects for the future of thin film photovoltaic are analyzed. The role of emerging innovative
technologies in a future photovoltaic energy scenario is discussed.
Ultrasonic Spray Deposition of CuInS2 Absorber Thin Films: Effect of Nozzle Frequency
Ass. Prof. Dr. Nurdan Demirci SANKIR, [email protected],
TOBB University of Economics and Technology Sogutozu Cad. No:43 (06560) Sogutozu Ankara
In this study copper indium disulfide (CuInS2) films have been deposited on soda lime glass substrates by spray
pyrolysis system equipped with new generation ultrasonic impact nozzle. With this system, precursor solution is
ultrasonically excited using piezoelectric crystals to generate very fine droplets. Droplet size, which is in micron size,
can be controlled by the oscillation frequency of the piezoelectric crystal. Pyrolysis conditions and film properties
are directly affected by the droplet size in the mist. Here, ultrasonic impact nozzle with two different oscillation
frequencies, 48 and 120 kHz, has been used to deposit CuInS2. While 48 kHz nozzle was generating 38 µm-sized
droplets, 120 kHz nozzle generated approximately 18 µm droplets for the aqueous precursor solutions. Copper (II)
chloride dehydrate (CuCl2), indium (III) chloride (InCl3) and thiourea (NH2CSNH2) were dissolved in double distilled
water as copper, indium and sulfur sources, respectively. The molar ratio of the Cu/In/S in solution and infuse rate
were kept constant for all samples while the solution amount was changing from 5 to 40 ml. SEM micrographs of
CuInS2 films showed that all sprayed films with 120 kHz nozzle were pin-hole free. On the other hand, some pinhole formations have been observed for 48 kHz impact nozzle. Moreover, films sprayed using solution more than
20 ml, could not retain their uniformity and peeled from the substrate for the 48 kHz nozzle. For the constant
substrate temperature and the nozzle-to-substrate distance, smaller droplet size resulted faster solvent
evaporation due to the higher surface to volume ratio. Most probably, the larger droplet size of 48 kHz resulted the
fast cooling of the substrate, and therefore, defect formation occurred on the surface. Cross sectional SEM studies
showed that, thickness of the films for both frequencies increased by increasing the solution amount as expected.
However, it was revealed that for the same solution amounts, films sprayed with 120 kHz nozzle were thinner than
48 kHz samples. Hence, it is possible to conclude that 48 kHz nozzle results higher deposition yield due to the more
precursor materials transferring to the surface with the help of larger droplets. Crystal structure of the spraydeposited films was confirmed using X-ray Diffraction (XRD) analysis. As expected crystallinity of the films increased
with increasing the solution amount. All films sprayed over 10 ml solution had intense characteristic chalcopyrite
peaks. No other secondary phases were observed on XRD data. The crystallite size of the films was ranging between
4 and 25 nm. Energy Dispersive X-Ray Analysis (EDAX) has been used to determine the chemical structure of
sprayed CuInS2 films. According to EDAX results all sprayed films with 120 kHz nozzle were sulfur rich for 15 kV
accelerating voltage. On the other hand, we obtained very close Cu, In, S ratios to the targeted 1:1:2 value for the
films 20 ml solution sprayed with 48 kH
Keywords: Copper indium disulfide, ultrasonic spray pyrolysis, chalchopyrite film, solar cells, impact nozzle
47
Attractive Features and Challenges for Flexible PV Module Manufacturing
Dr. Bülent Başol, CTO, EncoreSolar, San Jose, California, USA,
High efficiency solar cells can be processed over glass as well as flexible metal and polymeric substrates.
Manifacturing flexible CIGS devices has certain advantages but at the same time factors such as the nature of the
substrate surface, temperature limitations, etc. make manufacturing more difficult. Fabricating modules using
metal based CIGS solar cells has cost consequences but deployment of such flexible modules are attractive in terms
of installation cost and better integration with certain roofs. In this presentation we will discuss many such
challanges and advantages of manufacturing flexible CIGS devices and modules.
SESSION 5B: Operation and Performance, TOROS 1 HALL
Weighted Efficiency Measurment of PV Inverters: Ƞ İZMİR
MSc. İlker Ongun, [email protected]
Ege Universitesi Ege Meslek Yüksekokulu 35100 Kampus Bornova İzmir
Conversion efficiency of DC/AC inverters depends on some parameters and fluctuates over the input power of the
inverter. Since the PV inverters operate under a fluctuating input power supplied by the PV modules, conversion
efficiency must be measured against the weights of the probable power ranges which represent the various
irradiation values. This approach of having different weights for different irradiation ranges resulted in two basic
weighted conversion efficiency models of ƞ EURO and ƞ CEC . These two models consider the irradiation distribution
over the whole annual sunny time and prioritize the ranges with various weight factors. Since the irradiation
profiles vary around the planet, inverter efficiencies must be evaluated against local irradiation profiles to get more
precise annual energy yield estimation. Here we present ƞ İZMİR , a weighted conversion efficiency evaluation model,
derived from the İzmir irradiaton profile. This model has been developed in a way that it should be simple and
accurate so it has been matched with other models for its estimation capabilities. The results are discussed here
and suggestions being made.
Keywords: PV inverters, conversion efficiency, weighted efficiency, ƞ EURO , ƞ CEC , ƞ İZMİR
An Overview of CIS Based PV Power Systems
Hazar Atalay, Solar Nokta, TURKEY
[email protected]
Presentation will be mainly in 3 parts. 1st part will be about the products and technologies in the market. I will also
give some spec s which are relevant for the electricity production ( I may or may not indicate the brands of the
products, depending on you) In this part, I want to give some specific information about the panel that we are
using.
In the second part I will show some simulation results for specific regions with different technologies. There wont
be any brand on this slides. I will show some results from Germany-Italy- Turkey-UK
3rd part will be more of an installation or application presentation. Real data for CIS in the regions etc.
48
An overview of MPPT Techniques
Msc. Eşref Deniz, Assoc. Prof. Dr. Necdet Yıldız, Assoc. Prof. Dr. Numan Sabit
Çetin,
[email protected],
Ege University Solar Energy Institute, 35100 Bornova Izmir & Emek Cad. Bulvar Sok. Seza Apt. 5/A Muğla
Tracking of Maximum Power Point of a PV panel or PV panel array is of essential importance for yielding high
energy outputs from solar energy power systems. MPPT (Maximum Power Point Tracking) is utilized by on grid
inverters and charge regulators in order to make the system operate with maximum efficiency. The main mission of
the MPPT is to adopt the operating point of a module or array usually modifying the output voltage in order to
adapt the system to different irradiance conditions and also temperature variations. Therefore in theory and
practice a great number of MPPT methods have been developed. Among those methods, there are major
differences in terms of complexity of the systems, sensors used, convergence speed, cost, efficiency and hardware.
Within the scope of this study a wide range of MPPT techniques have been investigated. First studies about MPPT
techniques had started in the beginning of 70’s. The number of papers per year has grown considerably of the last
decades and remains strong. However, despite the grown number of MPPT techniques, methods that had been
developed were different versions of a handful of MPPT techniques. Among all methods investigated much focus
has been on Hill Climbing and Perturb and Observe methods. This paper outlines different versions of both method
and discusses the advantages and disadvantages of each technique. It overviews the main shortcomings of those
two conventional methods. All of the conventional techniques conduct the perturbing operations on the DC side of
the inverter. Due to continued perturbations of the voltage of solar panels, ripples are observed on the power
transmitted to the inverter side. If the perturbation step size is increased in order to increase the convergence of
the system the ripples on the power are also increased. On the other hand, control and operating processes on the
DC side of inverter increase the stress on the components on that side.
Keywords: MPPT, photovoltaic, inverter, perturb and observe, hill climbing
Modeling, Comparative Simulation and Practical Performance Analysis of a Stand-Alone PV
Power System in Turkey
Dr. Mete ÇUBUKÇU, [email protected]
Ege University Solar Energy Institute, TURKEY
This study aims to analyze and compare the performance of a stand-alone PV hybrid system located in Fethiye.The
system was built in off-grid configuration and employed a wind turbine and a diesel generator as supporting
supplies. System performance was calculated both by simulation and real time measurement. Comparison of
simulation and actual results were made. The results come up in this study would enable to define the factors
effecting performances of PV and/or hybrid power systems. The impact of the meteorological conditions, load
demands, and the characteristics of system components were also analyzed. The results were reported by using the
international evaluation parameters.
Keywords: Photovoltaics, Wind energy, Renewable hybrid power systems.
49
Modeling, simulation and control of three phase three level multilevel inverter for grid
connected photovoltaic system
Dr. Engin Özdemir, MSc. Serkan SEZEN, [email protected],
Kocaeli University, Turkey
Balıkesir University, Altınoluk Meslek Yüksekokulu, İskele Mah. Atatürk Cad. No:103 Altınoluk/Balıkesir, Turkey
This paper presents a control for a three phase three-level neutral clamped inverter (NPC) for grid connected
photovoltaic (PV) system. The maximum power point tracking (MPPT) is capable of extracting maximum power
from the PV array connected to each DC link voltage level. The MPPT algorithm is solved by Perturb&Observe
method. The MPPT system is integrated with the DC-link controller so that a DC-DC converter is not needed and the
output shows accurate and fast response. Synchronous Reference Frame (dq) Control Strategy is used for gridconnected PV system so that PI controllers are used to control easily DC-link voltage, active and reactive currents.
The validity of the system is verified through the simulations with MATLAB/Simulink and the results are compared
with Stationary Reference Frame (αβ) control in terms of control dynamics.
Keywords: Three phase three-level neutral clamped inverter; Maximum power point tracking (MPPT); Multilevel
inverter; Grid connected photovoltaic system; Synchronous Reference Frame (dq) Control
50
SESSION 6A : DSSC, TOROS 1 HALL
Photovoltaic performance of bifacial dye sensitized solar cell using chemically healed binary
ionic liquid electrolyte solidified with SiO2 nanoparticles
M. Burak Coşar, Prof. A. Macit Özenbas, [email protected], Middle East Technical University, Dept. of
Metallurgical and Materials Eng. Middle East Technical University 06800 Ankara Turkey
Photovoltaic performance of bifacial dye sensitized solar cell using chemically healed binary ionic liquid electrolyte
solidified with SiO2 nanoparticles Mustafa Burak Cosar*,**, Kerem Cagatay Icli***,**, Halil Ibrahim Yavuz*,**, A.
Macit Ozenbas*,** *Department of Metallurgical and Materials Engineering, Middle East Technical University,
06800 Ankara / Turkey **Center for Solar Energy Research and Applications (GUNAM), Middle East Technical
University, 06800 Ankara / Turkey ***Micro and Nanotechnology Graduate Program, Middle East Technical
University, 06800 Ankara / Turkey Mostly used electrolytes in high efficiency dye sensitized solar cells (DSSCs) are
solvent based volatile liquid electrolytes which cause degradation of the cells at ambient conditions. Main strategy
to improve the stability of DSSCs is to find non-volatile counterparts of conventional solvents acetonitrile,
valeronitrile, methoxypropionitrile, etc. Several groups have investigated application of different hole conducting
mediums like ionic liquids, polymer electrolytes, organic-hole transport materials, and inorganic semiconductors.
However, none of these materials achieved 10% efficiency of solvent based electrolytes because of low diffusion
rate of redox species and wetting ability. Besides all ionic liquids are promising candidates as they have thermal and
electrochemical stability and hydrophobicity which also have comparable efficiencies with solvent based
electrolytes. In this study, we investigated the effect of electrolyte composition, photoanode thickness, and the
additions of guanidinium thiocyanate (GuSCN), N-methylbenimidazole (NMB), and SiO2 on the photovoltaic
performance of DSSCs. A bifacial transparent DSSC is realized and irradiated from front and rear sides. The devices
give maximum photovoltaic efficiencies for 70% PMII / 30% (EMIB(CN)4) electrolyte composition and 10 µm thick
TiO2 photoanode coating which is considered to be the ideal coating thickness for the diffusion length of
electrolyte and dye absorption. A significant increase in the photocurrent for DSSCs with optimum molarity of 0.1
M GuSCN was observed due to decreased recombination which is believed to be surface passivation effect at
photoanode electrolyte interface suppressing recombination rate. Moreover, optimum NMB molarity was found to
be 0.4 for maximum efficiency. Addition of SiO2 to the electrolyte both as an overlayer and dispersed particles
enhanced rear side illuminated cells where dispersed particles are found to be more efficient for the front side
illuminated cells due to additional electron transport properties. Best rear side illuminated cell efficiency was 3.2%
compared to front side illuminated cell efficiency of 4.2% which is a promising result for future rear side dye
sensitized solar cell applications where front side illumination is not possible like tandem structures and for cells
working from both front and rear side illuminations. Keywords: dye s
Keywords: dye sensitized solar cell; ionic liquid; SiO2 nanoparticles; bifacial sides illumination.
ZnO Nanowire Dye Sensitized Solar Cell
Dr. Bayram Kılıç, [email protected],
Yalova University Engineering Faculty Energy Systems Engineering Department 77100 Yalova Turkey
Zinc oxide (ZnO) nanowires were grown on FTO substrate by using the hydrothermal method. The study is mainly
focused on the rational synthesis, optic and structure analysis and novel properties of ZnO nanowires which can be
used in dye sensitized solar cell. Structural and optical characterizations were performed by scanning electron
microscopy (SEM), atomic force microscopy (AFM), x-ray diffraction (XRD), photoluminescence (PL), absorbance
and Raman spectroscopies. Nanowires structures were used as the wide band-gap semiconducting photo-electrode
in dye sensitized solar cell (DSSCs). Solar cell made from ZnO nanowire at 50 nm radius and several tens micron
lengths showed high solar conversion efficiency (η) of 2.1% and incident photon current efficiency (IPCE) 35% using
nanowire/N719 dye/I-/I-3 electrolyte.
Keywords: Dye Sensitized Solar Cell (DSSC), N719, N3, Zinc oxide, Nanowires, SEM, AFM, Raman.
51
Novel Perylene Diimide-Benzimidazole Type Dye Sensitization of Fullerenes for Organic
Photovoltaic Devices
Haluk Dinçalp,*, Oğuzhan Çimen, Tayebeh Amerib, Christoph J. Brabecb, Siddik İçli
Department of Chemistry, Faculty of Arts and Science/Celal Bayar University, TURKEY
Institute of Materials for Electronics and Energy Technology (I-MEET)/Friedrich-Alexander-University, GERMANY
Solar Energy Institute/Ege University, TURKEY
[email protected]
Organic photovoltaics (OPVs) have gained much attention because of their inexpensive fabrication and flexible
substrate compatibility with respect to their inorganic counterparts such as traditional silicon-based solar cells [1].
They are generally comprised of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester
(PCBM) blend giving high power conversion efficiency in the past. In recent years, much works have been done for
improving the efficiency by using different organic polymers, oligomers or small molecules with different blend
systems. One of the most preferred small molecule cores is perylene diimides (PDIs) showing good liquid crystalline
behavior, high electron mobility and excellent photochemical and thermal stability under solar irradiated
conditions [2]. PDIs can be functionalized with different positions (peri-, bay- or ortho- positions) in order to cover
their absorption spectra to whole solar region and also to improve their solubility in organic solvents, which is
important for evaporation procedure in OPV fabrication [3].
We have functionalized PDI core structure at bay positions by attaching new benzimidazole group and obtained BIPDI structure, shown in Figure. In this study, optical properties of the novel dye have been investigated by
absorption, steady-state and time-resolved photoluminescence spectroscopy in different solution phases and also
in solid state. OPV devices have been fabricated with different configurations by doctor-blading technology and
also morphological properties of the devices have been evaluated. Photocurrent behaviors of the contributors have
been investigated by external quantum efficiency (EQE) measurements. Also, transport properties of the devices
have been investigated in detail.
Quasi-Solid State Dye-Sensitized Solar Cell Applications of N-doped TiO2 Photoanodes
Halide Diker, Assoc. Prof. Dr. Canan Varlıklı
Prof. Dr.Elias Stathatos
[email protected],
Ege University Solar Energy Institute, 35100 Bornova Izmir
Nitrogen doped TiO2 nanocrystalline particles are synthesized by a microwave assisted hydrothermal growth
method using different amines as nitrogen sources at different concentrations. XRD, UV-Vis DRS, FE-SEM and XPS
were used for the characterization of nanoparticles. All of the samples exhibited pure anatase phase. Crystalline
sizes of N-doped TiO2 samples were decreased about 2-3 nm and additionally optical band gaps were reduced
compared to the undoped TiO2 samples. N-doped TiO2 samples are used in the preparation of photoanodes for
quasi-solid state dye-sensitized solar cell applications. Characterizations of the cells are performed under standard
conditions (1000W/m2 irradiation at AM 1.5). Current density enhancement of 11% to 58% is achieved with the use
of N-doped TiO2 photoanodes.
52
Surface modification of FTO nanoparticles for enhanced efficiency of DSSCs
MSc. Kerem Çagatay İçli, [email protected],
Middle East Technical University Dept. of Metallurgical and Materials Eng. D-311 06800 Ankara Turkey
Surface modification of FTO nanoparticles for enhanced efficiency of DSSCs Kerem Çağatay İÇLİ*,***, Ahmet Macit
ÖZENBAŞ**,*** * Middle East Technical University, Micro and Nanotechnology Prog., Ankara, Turkey ** Middle
East Technical University, Metallurgical and Materials Eng. Dept., Ankara, Turkey ***Center for Solar Energy
Research and Applications (GÜNAM), Middle East Technical University, Ankara, Turkey Dye sensitized solar cells
(DSSC) have been attracting attention since their invention. Low-cost production and moderate efficiency values
obtained in these cells are main advantages of the DSSCs, however commercialization requires higher efficiency
values. Strategies for improved efficiencies include high performance sensitizers, novel hole conductors and
different anode material architectures. Application of transition metal oxides other than TiO2 like SnO2, Nb2O5,
ZnO and ZrO2 have been tried by many researchers but none of them can compete with TiO2. SnO2 is a promising
candidate DSSC anode material as it provides higher electron mobilities compared to TiO2. Its electronic properties
can be tailored upon doping with fluorine or antimony. However, cells made from SnO2 suffers from high
recombination rates. One strategy to solve this problem is the modification of SnO2 surface with other metal
oxides and create an energy barrier for suppressed recombination referred as core-shell type anodes. Electrically
conductive fluorine doped tin dioxide (FTO) is a well-known TCO material used in conductive substrates in DSSCs.
Production and application of nanoparticles of FTO are promising for enhanced electronic transport and also as a
cheap alternative to CVD produced FTO coating which is the most expensive part of a DSSC. In this work, FTO
nanoparticles were produced by sol-gel methods and applied in DSSCs. Thin shell coatings of ZnO, TiO2, MgO and
Nb2O5 were deposited on the anode from aqueous solutions in order to enhance the cell parameters of FTO
nanoparticles. Produced FTO nanoparticles were characterized with SEM, TEM, XRD and BET measurements.
Electrical characterizations were conducted with four point resistivity measurements and Hall effect studies. DSSCs
were characterized under simulated AM1.5 conditions. A plain glass electrode without TCO coating which is made
of electrically conductiveFTO particles itself will also be presented for future TCO-less DSSC applications and results
will be given. Keywords: Dye sensitized solar cell, FTO nanoparticle, core shell structure.
Keywords: Dye sensitized solar cell, FTO nanoparticle, core shell structure.
Hybrid Ultraviolet Photodetector Applications
Napthalenediimide: N-doped Titanium dioxide
in
the
Consept
of
Polyfluorene:
MSc. Görkem Memişoğlu, Assoc. Prof. Dr. Canan Varlıklı, MSc. Halide Diker, [email protected],
Ege University Solar Energy Institute, 35100 Bornova Izmir
UltraViolet PhotoDetectors (UV-PDs) have numerous application areas such as UV curing, sterilization, medical
sector, smoke and arc detection [1]. Especially UVA (315-400 nm) radiation is important because it arrives earth
crust by diffuse or direct solar radiation due to its longer wavelength than UVB (280-315 nm) and UVC (280-315
nm) that are absorbed partially and completely in the atmosphere, respectively [2]. We have investigated a UV
photodetector system within ITO/PEDOT:PSS/PFE:BNDI/Al system and we obtained the photoresponsivity of 410
mA/W at −4 V under 1 mW/cm2 UV light at 368 nm [3]. Hereby, we are presenting PFH:BNDI:N-TiO2 based hybrid
ultraviolet photodetectors that are studied optically and electrically. Pure TiO2 nanoparticles and three different
nitrogen sources (dipropylamine (DPRYL), diethanolamine (DETOH), ammonium hidroxide (NH4OH)) in the TiO2
nanoparticles [4] were used in the PFE:BNDI blend. In the device configuration of ITO/PEDOT:PSS/[(PFE:
BNDI)(3:1):NH4OH] [9:1]/Al at -4 V bias under 1 mW/cm2 UV radiation at 368 nm wavelength, 545 mA/W and 597
mA/W photoresponsivities are obtained, at RT and at 60 oC, respectively. It has seen that the photodetector
performances were strongly dependent on the nitrogen source nature in titanium dioxide nanoparticles that is
dispersed in PFE:BNDI blend. [1] J. of Applied Physics, 79 (1996) 7433-73 [2] Advanced Materials, 21 (2009) 2034-39
[3] International Journal of Photoenergy, 2012 (2012) ID 936075 [4] Energy, 36 (2011) 1243-54
Keywords: Hybrid UV PhotoDetector, conjugated polymer, napthalenediimide, N-doped TiO2
53
SESSION 7A: Organic solar cells, YILDIZ HALL
Organic Solar Cells with Benzotriazole-Based Conjugated Copolymers as Electron Donors
Assoc. Prof. Dr. Ali Çırpan, METU, TURKEY
[email protected]
Benzotriazole based conjugated copolymers were synthesized via a typical Suziki coupling polymerization. Optical
and electrochemical studies indicated that polymers have desirable HOMO-LUMO and band gap energy levels,
enabling efficient electron transfer when blending with fullerene derivatives. Photovoltaic properties of copolymers
mixed with [6,6]phenyl-C61-butyricacid methylester (PCBM) were investigated. Polymer:PCBM blend exhibited the
device performance with an open circuit voltage of 0.76V, short circuit current of 4.2 mA/cm2 and power
conversion efficiency of 1.06 % under Airmass 1.5 Global (AM1.5G, 100 mW/cm2) illumination.
Organic Solar Cells
Dr. Elif Alturk Parlak, [email protected],
TÜBİTAK UME Tübitak Gebze Yerleşkesi Gebze
700 hours stability of Large Area Organic Solar Cell of Poly (p-phenylene-ethynylene)-alt-poly(p-phenylenevinylene) polymer Elif Alturk Parlak*, Nesrin Tore, Pelin Aydogan Kavak, Christoph Ulbricht , Daniel A.M. Egbee We
have fabricated large area organic solar cells based on anthracene-containing poly (p-phenylene-ethynylene)-altpoly (p-phenylene-vinylene) (PPE-PPV) polymer (AnE-PVstat) solar cells. The stabilities of AnE-PVstat solar cells with
different geometries were compared. ISOSL1 stability test of AnE-PVstat solar cells was also performed. AnE-PVstat
large area solar cells are stable for 700 h under standart solar irradiation of 100mW/cm2 (AM1.5G) at ambient
conditions. T80 values of AnE-PVstat: PCBM solar cells are 286 h for Geometry A which is smaller area and 95 h for
Geometry B that is larger area
Keywords: AnE-PVstat, large area, PPE-PPV, organic solar cell
A Novel Low-cost n-Type Semiconductor for Organic Photovoltaics: Potential Alternative to
PCBM
PhD St. Burak Gültekin, PhD. St. Deniz Ergun, Assoc.Prof.Dr. Ceylan Zafer
[email protected],
Ege Universitesi Güneş Enerjisi Enstitüsü, 35100, Bornova, İzmir
In this study, we present a new low-cost n-type organic molecule based on naphthalene with high electron
withdrawing cyano moieties as an alternative acceptor material for organic photovoltaic applications. The
structural properties of the molecule have been determined by TOF-MS, H1-NMR, C13-NMR, and IR- spectroscopy.
The photopysical and the electrochemical properties of the acceptor material have been determined by UV-Vis,
Fluorescence Spectroscopy, and Cyclic Voltammetry. For photovoltaic applications, bilayer heterojunction type
organic photovoltaics have been fabricated and CN4NDI-EH used as the acceptor. The photovoltaic performance
measurements have been carried out under standard conditions while ZnPc/PDI has been used as the reference.
Key Words: n-type semiconductor, organic photovoltaics
54
Photovoltaic Performance Improvement Of Triarylamine Substituted Quinoxaline “Push-Pull”
Dyes For DSSCs
Assoc. Prof. Dr. Ceylan Zafer, B.Sc. Kadir Demirak, B.Sc. M. Zeliha Yigit, MSc. Mustafa Can, MSc. Deniz A. Ergun,
Assoc.Prof.Dr. Serafettin Demiç
[email protected],
Ege Üniversitesi Güneş Enerjisi Enstitüsü 35100 Bornova/İzmir
Four new metal free triarylamine and qunoxaline dyes were synthesized. The organic dyes are based on triphenyl
amine groups as a strong donor and cyanoacrylic acid (DYE-1 and DYE-2) and carboxyl groups (DYE-3 and DYE-4) as
a strong acceptor. DYE-1 and DYE-2 dyes had thiophene and phenyl in the π-conjugated bridge respectively in order
to transfer of electron from donor through strong acceptor. DYE-3 and DYE-4 contained quinoxaline with two
carboxyl groups and the phenazine with one carboxyl group in the core structure respectively by constructing
planner structure. Two triphenylamine donor groups were bounded to opposite sides of the cores. The structure of
promising dyes was characterized by 400 MHz H1- and C13- NMR while optically characterizations were performed
by UV-Vis absorption and fluorescence spectrophotometer. Highest occupied molecular orbital (HOMO) and lowest
unoccupied molecular orbital (LUMO) energy levels and Eg were obtained by cyclic voltammetry method. TiO2
based dye sensitized solar cells (DCCS) were fabricated and their electrical characterizations were determined
under simulated AM 1.5 irradiation with 100mW/cm2.
Keywords: DSSC
Molecular Engineering Of New Quinoxaline Based Acceptors to Improve Charge Generation in
Organic Photovoltaics
MSc. Deniz Aykut Ergün, B.Sc. M. Zeliha Yigit, B.Sc. Kadir Demirak, MSc. Mustafa Can, Assoc. Prof. Dr. Serafettin
Demiç, Assoc. Prof. Dr. Ceylan Zafer,
[email protected],
The Solar Energy Institute, Ege University
Ege Üniversitesi Güneş Enerjisi Enstitüsü 35100 Bornova/İzmir
We
demonstrates the bulk hetero-junction solar cells based on the blends of promising and novel synthesized acceptor
molecules and regioregular poly (3-hexylthiophene-2,5-diyl) (P3HT). Both molecules contained triphenyl amine
groups as a strong donor. However, (DYE-5) molecule was comprised by quinoxaline core as a acceptor while two
cyano groups on quinoxaline core of (DYE-6) were redounded as a strong acceptor property to molecule.
Photoluminescence and photo induced absorption measurements were performed in order to obtain optical
properties. For identification of change in energy gap, cyclic voltammetry method was examined. The devices were
fabricated in different ratio with P3HT, and electrical characterization was performed under simulated AM 1.5
irradiation with100mW/cm2.
Keywords: Organic Solar Cell, bulk hetero-junction
55
SESSION 7B: Plasmonics and light trapping, TOROS 1 HALL
Effect of surface type on structural and optical properties of Ag nanoparticles formed by
dewetting
Dr. Alpan Bek, MSc. İrem Tanyeli, Mr. Hisham Nasser
MSc. Fırat Es, Prof.Dr. Raşit Turan
[email protected],
Middle East Technical University
Physics Department, Dumlupinar Blvd. 1, 06800 Cankaya Ankara
Integration of an array of Ag nanoparticles
(AgNP) in solar cell architecture is expected to increase light trapping through near field enhancement and
plasmonic scattering. Successful placement of countless number of AgNPs at the macroscopic scale of the solar cell
area is a key factor for their beneficial use. AgNP decoration of any surface or interface at the macro-scale calls for
a self-organized fabrication method such as dewetting. Optical properties of a 2D array of AgNPs are known to be
very sensitive to their shape, size, and inter-particle distance. We show that these parameters strongly depend on
the type of the substrate used. We study the variations in structural and optical properties of dewetting based
AgNPs on 5 different substrates that are commonly used in solar cell technologies. We observe a strong correlation
between average nanoparticle size and its distribution and substrate thermal conductivity and surface roughness.
Keywords: plasmonics, dewetting, thermal conductivity, surface roughness
Engineering the Broadband Spectrum of Plasmonic Nanoantenna Surfaces
Assoc. Prof. Dr. Kursat Sendur, MSc. Umut Tok, [email protected],
Sabanci University Orhanli - Tuzla 34956, Istanbul
Plasmonic structures are promising tools to improve the energy conversion efficiency in thin film solar cells because
of their capability of localizing and/or trapping light within the active region of thin film solar cells. Spectral
responses of plasmonic antennas are frequency dependent and exhibit resonance behavior. They usually operate in
a narrow spectral region. On the other hand solar spectrum spans a broad spectral range. In order to improve
energy conversion efficiency over the whole solar spectrum, broadband plasmonic structures operating within this
range are emerging needs. In this study, broadband spectra of plasmonic nanoantenna surfaces are engineered.
The honeycomb nanoantenna array is based on an asymmetrical hexagonal grid with periodically arranged
nanostructure building blocks. Each hexagonal building block is in fact a Wigner-Seitz unit cell of the periodic lattice
structure. The asymmetry of the unit cells provides the wideband operation to the structure via supporting multiple
resonances. Beside of this, directionality is induced by the array factor of the lattice structure or it can be
interpreted as vectoral superposition of the fields produced by the Wigner-Seitz unit cells, far-zone optical fields
interfere constructively or destructively in different directions.
Keywords: broadband, nanoantenna, plasmonics.
56
Understanding the realistic plasmonic properties of dewetting formed Ag nanoparticles in
large area solar cell applications
Dr. Gürsoy B. Akgüç, Prof.Dr. Oğuz Gülseren, MSc. Mehmet Can Günendi, [email protected],
Bilkent Üniversitesi Fizik Bolumu sa214 Ankara
The effects of substrates with technological interest for solar cell industry are examined on the plasmonic
properties of Ag nanoparticles fabricated by de-wetting technique. Both surface matching and propagator
techniques are used in numerical simulations to describe plasmonic properties and to interpret experimental data.
The uncertainty on the locations of nanoparticles by the substrate in experiment is explained by the simulations of
various configurations of them. The change in plasmon resonance due to the location of nanoparticles with respect
to the substrate, interactions among them, their shapes, and sizes as well as dielectric properties of substrate are
discussed theoretically and commented on implications for the experiment.
Keywords: solar cell, thin films
Plasmonic Nanoparticles for Photovoltaic Applications
MSc. Seval Sarıtaş, Dr. Emel Sungur Özen, [email protected],
Bilkent University, Department of Physics, Ankara, 06800, Turkey.
Plasmonics is a promising approach to enhance the light trapping properties of thin-film solar cells. Excitation of
surface plasmons is characterised by a strong scattering and an enhancement of the electric field around the
vicinity of the metal nanoparticle. These properties can be used to reduce the losses du to incident light reflection
and to increase the optical absorption within the cell [1]. Absorption can be enhancenced in the required
wavelength region by tuning the surface plasmon resonance controlling the nanoparticle’s size, shape, and local
dielectric environment. In this study we focus on the obtaining of plasmonic Ag nanoparticles by laser induced
dewetting of metastable thin films. Ag thin films were obtained by thermal evaporation on different substrates. The
dewetting phenomenon was studied as a function of film thickness, laser power density and irradiation times.
Obtained nanoparticle arrays were characterized by Scanning Electron Microscopy (SEM) and Atomic Force
Microscopy (AFM) and the optical properties were investigated by UV-Visible spectroscopy. The size and
characteristic length dependency of nanoparticles on film thickness have been determined as well as the effect of
substrate type. Embedded nanoparticles and multilayered structure have also been investigated with a view to
characterize their plasmonic resonance properties. This research is supported by BMBF-TÜBITAK project
"RainbowEnergy". [1] H.A.Atwater and A. Polman, "Plasmonics for improved photovoltaic devices", Nature Mater.
9, 205-210 (2010).
Keywords: Plasmonic nanoparticles, light trapping photovoltaics.
57
Efficient Light-Trapping in Inverted Nano-Pyramid Thin Crystalline Silicon Membranes for
Solar Cell Applications
Dr. Selçuk Yerçi, Dr. Anastassios Mavrokefalos, Dr. Sang Eon Han, Prof.Dr. Gang Chen, [email protected],
Massachusetts Institute of Technology 77 Mass. Ave. 7-008, Cambridge, MA, 02139
Thin-film crystalline Si (c-Si) solar cells with light-trapping structures can enhance light absorption within the
semiconductor absorber layer and reduce material usage. We demonstrate that an inverted nano-pyramid lighttrapping scheme for c-Si thin films, fabricated at wafer-scale via a low-cost wet etching process, significantly
enhances absorption within the c-Si layer. A broadband enhancement in absorptance is achieved with minimal
angle dependence. We further show that c-Si films less than 10μm in thickness can achieve absorptance values
comparable to that of planar c-Si wafers thicker than 300um. Furthermore the surface area increases by only a
factor of 1.7, which limits surface recombination losses in comparison with other nanostructured light-trapping
schemes. Therefore, these structures will not only significantly curtail both the material and processing cost of solar
cells, but also achieve the high efficiency required to enable viable c-Si thin-film solar cells. *This work is funded by
DOE EERE Sunshot program and UC Berkeley SINAM Center.
Keywords: crystalline silicon, light-trapping, thin film, solar cells
Deposition and Sulfurization Processes of CZTS Absorber Layer on Ti and Mo Coated SLG for
Solar Cells
Dr. Mehmet Ali Olğar, Prof.Dr. Lutfi Özyüzer, MSc. Şebnem Yazıcı, Prof.Dr. Ekrem Yanmaz, Assoc. Prof. Dr. Gulnur
Aygun OZYUZER, Dr. Ayten Cantaş, [email protected],
Karadeniz Technical University, science faculty, department of physics, Merkez/Trabzon
Deposition and Sulfurization Processes of CZTS Absorber Layer on Ti and Mo Coated SLG for Solar Cells M.A. Olgar,*
H. Saglam, S. Yazici, A. Cantas, M. Kurt, G. Aygun, E. Yanmaz, L. Ozyuzer Department of Physics, Karadeniz Technical
University, Merkez, 61080, Trabzon, Turkey *Corresponding author E-mail address: [email protected] Phone:
+90-462-3774194, Fax: +90-462-3253195 [keywords] Thin film solar cells, Cu2ZnSnS4 (CZTS) thin film, Sulfurization,
DC magnetron sputtering. The thin film solar cell technologies receive increasing interest from the photovoltaic
industry because of their potential producing low cost electricity compared to wafer based crystalline Si
technologies. Although CIS and CIGS such some important absorber layers and have maximum efficiencies
approaching %20 [1], they contain rare and expensive materials like In, Ga, Te and also include toxic elements like
Cd and Se that represent disadvantages. Cu2ZnSnS4 (CZTS) can be good choice for new absorber layer in terms of
presenting absorption coefficient over 10-4 cm-1 and band gap energy near 1.45 eV [2]. Unlike the others, CZTS
thin films are one of the most viable materials which contain earth abundant elements for low cost and less toxic
elements for the environment. In this study, we fabricate CZTS absorber layer with dc magnetron sputtering in-situ
growth by two steps. The first step is sequential metallic precursor deposition layer by layer on Mo and Ti coated
soda lime glass (SLG). We optimize the order and thickness of each layer, Cu, Zn and Sn. Due to the matching
thermal expansion coefficient of titanium with CZTS, we deposited Ti on SLG substrate as a back contact layer. By
this way, we can compare advantages and disadvantages of the new back contact Ti and traditional back contact
Mo. These layers are then heated up in a Sulphur (S) + Argon (Ar) atmosphere. Then we find the optimum method
and temperature for sulfurization process. The datails of the fabrication process will be discussed. *This research is
partially supported by TUBİTAK project with number 112T068. References [1] I. Repins et al., Prog. in Photovolt.:
Research and Applications 16, 235–239 (2008). [2] J.M. Raulot et al., J Phys Chem Solids 66, 2019–2023 (2005). [3]
H. Araki et al., Thin Solid Films 517, 1457-1460 (2008).
Keywords: Thin film solar cells, Cu2ZnSnS4 (CZTS) thin film, Sulfurization, DC magnetron sputtering.
58
SESSION 8 – Present and Future of Solar energy in MENA Countries and Turkey,
ALADAĞ HALL
Cost and Efficiency to Achieve Grid Parity
Dr. Fedaa Ali, [email protected],
Qatar Energy and Environment Research Institute, Qatar- Doha Al Rayan Road Qatar Foundation Energy and
Environment I stitute PO. Box 5825
Although direct conversion of solar energy to electricity by photovoltaic cells, or thermal energy in concentrated
solar power systems, is emerging as a leading contender for next-generation green power production, the solar
energy contribution to energy outlook begins from a much smaller base than oil and natural gas, where the
infrastructure as well as human capacity to support solar power production on the same scale does not currently
exist. Hence, it is vital to select the research and development portfolio that will reduce risk in investment to
embark upon solar projects, and help motivate deployment of new technologies. The photovoltaic's (PV) area is
rapidly evolving based on new materials and deposition approaches. At present, PV is predominately based on
crystalline and polycrystalline Si and is growing at >40% per year with production rapidly approaching 3
gigawatts/year with PV installations supplying <1% of energy used in the world. Crystalline silicon-based systems
will remain the dominant photovoltaic technology in the short term, but thin films are steadily increasing their
market share too. There is also the use of multi-junction cells or hybrid devices organized at the nanoscale, the
nanostructured photovoltaics. Increasing cell efficiency and reducing manufacturing expenses are critical in
achieving reasonable costs to achieve grid parity. The paper includes analysis for the most challenging technological
barriers to achieve low-cost, high performance power conversion for photovoltaics, and promising R&D paths to
meet such challenges.
Keywords: Solar energy, solar photovoltaic, grid parity, PV materials, and PV technology generations
Potential of Photovoltaic Industry in Egypt
Dr. Osama Tobail, [email protected],
Egypt Nanotechnology Center (EGNC), Smart Village, Building 121, Cairo-Alexandria Desert Road, 12577 Egypt
Photovoltaic (PV) market is dominated by Europe, especially Germany and Spain. However, the PV industry leaders
recently exist in Asia. The huge market growth require industry growth, but with competitive cost. The electricity
shortage in Egypt makes transferring to photovoltaic technology necessary, especially with the high solar radiation.
The only reason why grid parity is not yet reached in Egypt is the elevated subsidiary of congenital electricity. If this
subsidy is transformed to incentives for using and manufacturing solar cells, the situation will vary. This article
shows that transferring PV industry to Egypt has a potential of cost saving of 5.7%, which could be translated either
into competitive price or higher return on investment. This work is not a feasibility study. However, based on the
cost structure of each phase in the PV industry value chain, the benefit (5.7% cost reduction potential) of
transferring the industry to Egypt is worthy to accomplish the needed feasibility study.
Keywords: Si solar cells, photovoltaic industry, cost structure
59
Economic Impacts of the Renewable Energy Sector; Supply Chain Approaches and the Search
for Methodology
Dr. Baha Kuban, [email protected],
Turkish National Photovoltaic Technology Platform - UFTP
Dolaybagi- Baglar Ckmz. 4, A.Hisar, Istanbul/Turkey
Macro-economic impacts of renewable energy technologies is an important issue of great public interest, especially
today when job creation is very high on the agenda of policy makers worldwide. As socio-economic and
environmental issues get increasingly related, the general consensus is that, decentralized power generation
through renewable energy technologies particularly solar and wind, generate longer downstream and upstream
externalities that compensate with wide margins those lossed incurrred from job losses from the phasing out of
conventional fossil capacity. On the the hand, large number of studies indicate that discussion and comparison
problems remain. The main contribution of economic and especially employment impact studies should be to
provide a better understanding of key parameters and mechanisms that determine and/or influence the economic
impacts of renewable energy technologies. The solar industry is one of the novel distributed power generation
technologies in the forefront of the job creation impact of increased renewable energy power generation. The
supply chain for solar photovoltaics has provided for several tens of thousands of jobs in directly and much more
indirectly. Solar photovoltaics has been assessed as a net contributor to the employment equation, particularly in a
distributed power generation structure. The particular contributon of the photovolaic supply chain demands a
detailed look at specific steps of the production process from raw materials and consumables to manufacturing
machinery, production lines and installation of systems of all scales. It is also a well known fact that solar
photovotaics are unbeatable in local job creation in small scale installations. This paper will look at the main points
of models to evaluate economic impacts as well as venture to take a qualitative look on potential supply chain
opportunities for the Turkish industrial landscape vis a vis the economic impact of larger penetration of solar
electricity into the power supply.
Keywords: Solar PV, Economic Impacts, Supply Chain Approaches
Israel and Turkey: Case studies for the massive introduction of renewables
Prof. David FAIMAN, Blaustein Institutes for Desert research, Ben-Gurion University of the Negev, Israel.
The paper will discuss each country’s electricity requirements within the context of past generation statistics. It will
discuss the extent to which photovoltaics and wind could provide for future needs, what the approximate costs
would be, and how funding might be provided.
60
SESSION 9A: Concentrated PV Systems, ALADAĞ HALL
Photovoltaics and Global GHG Reduction
Prof. David FAIMAN, Blaustein Institutes for Desert research, Ben-Gurion University of the Negev, Israel.
The talk will review rising global CO2 emissions through the year 2012 and the specific contribution of China,
currently the world’s largest emitter. It will estimate the rate at which photovoltaic (PV) plants must be introduced
into that country in order to freeze emissions at their present level, and compare this rate with current PV module
production capacity and land availability. The critical importance of concentrator photovoltaics (CPV) will be
emphasized. Taking wind power into consideration, the analysis will be broadened to global proportions. It will be
concluded that China holds many of the keys, and that if that country will take a bold lead then the rest of the
world will be able to follow - to the advantage of all.
Thermal Stability Analysis of Concentrating Single-Junction Silicon and 3C-SiC-based Solar Cells
Prof. Ali Rostami, MSc. Hamid Heidarzadeh, Dr. Hamed Baghban, Dr. Hassan Rasooli, Dr. Mahboubeh Dolatyari
[email protected],
University of Tabriz
Tabriz, Iran
29 Bahman, BLVD., Faculty of Electrical and Computer Engineering, University of Tabriz,
Concentrating photovoltaic systems have been used to deliver high electrical power in comparison to nonconcentrated solar power systems. Concentrator solar cells provide the possibility of obtaining very competitive
cost by substitution high band-gap materials by silicon that make an economic concentration of power incident on
the photovoltaic cell due to thermal stability. This means the commercial opening of a new industrial road to the
photovoltaic sector to cut costs drastically. In this paper we have analyzed the operation characteristics as well as
thermal stability of silicon and 3C-SiC-based solar cells under illumination greater than one sun. These analyses can
be generalized to show the operation characteristics of a single junction concentrating solar cell. We have shown
that the light intensity incident on a solar cell alters solar cell performance parameters, including short circuit
current, open circuit voltage, fill factor and efficiency of solar cell due to variation in the device temperature. For
this reason we have calculated the temperature-dependence material band gap to obtain the current density
variation under different temperature. Then, we have evaluated the open circuit and fill factor temperature
dependency and finally, we have investigated the efficiency and output power in different temperatures and
intensities. It has been concluded that 3C-SiC presents considerable thermal stability for high intensity application
unlike single junction silicon solar cell. For the temperature range of 300oK-1100oK the maximum achievable
efficiency for silicon based solar cell decreases from 30% in 300oK to near 1% in 1100oK while the obtained
efficiency of 3C-SiC-based cell surpasses from silicon-based cell at temperatures near 700oK.
Keywords: concentrator, photovoltaic, solar cell efficiency, temperature stability
61
A Comparative study for structural and electronic properties of AlN compound
Assoc. Prof. Dr. Rezek M. S. Estaiteh, Prof.Dr. Senay Katirgioglu, [email protected],
Palestine Technical University-khadoorie P.O.Box 7, Tulkarem westbank - Palestine
The FP-LAPW calculations based on DFT within LDA, PBE-GGA, EVex−PWco−GGA, and EVex−GGA-LDAco schemes
are introduced for the structural and electronic properties of AlN in WZ, ZB, and RS phases. It is found that WZ-AlN
is the stable ground state structure and makes a transition to the RS phase at low transition pressure. According to
the present calculations, the ZB phase of AlN makes also a transition to RS phase at low transition pressure. The
present EVex−PWco−GGA calculations have provided more reasonable results than the others (LDA, PBE−GGA,
EVex−GGA-LDAco) for both structural features and large energy gaps of AlN phases close to the available
experimental and theoretical ones. But, the largest energy gaps of the WZAlN, ZB-AlN, and RS-AlN structures very
close to the available measured and calculated ones are obtained by the present MBJP calculations. Hence, MBJP
scheme used in OEP calculations is considered to be a good approach for further works comprising the electronic
band structure calculations of AlN phases.
Keywords: AlN, FP-LAPW, DFT, Structural Properties, Electronic Properties, optical properties
Horizontally staggered light guides for high concentration CPV applications
Özgür Selimoğlu, [email protected]
GÜNAM, Middle East Technical University, TURKEY
Concentrating Photovoltaic systems are good candidates for low cost solar energy production. CPV means replacing
expensive semiconductor photovoltaic with the cheaper optics. Although the idea is simple, classical CPV systems
have several problems such as thickness, expensive PV cells, too strict tracking tolerance and overheating.
Light guide systems are good alternatives to classical Fresnel lens based CPV systems. Light-guide based CPV
systems have potential to overcome most of the problems of the CPV systems. A light-guide based solar module is
developed by GUNAM to create the know-how related to light guide solar systems and realize a cost effective solar
module.
62
Session 9B: Joint Session with EPHESTUS & CSP, TOROS 1 HALL
High-Performance Solar Thermal Electricity Generation
Abraham Kribus, [email protected]
School of Mechanical Engineering, Tel Aviv University, Tel Aviv, Israel
High conversion efficiency is key to the future success and competitiveness of solar thermal power plants. Current
solar thermal plants use turbines with 35-42% cycle efficiency, and achieve overall annual solar-to-electricity
efficiency of about 15–18%, which is too low. Advances in thermodynamic cycles and high-temperature solar
receivers are needed for significant increases in efficiency. Several possible solutions offering higher performance
will be described. Supercritical steam cycles are already used in conventional power plants, providing 45-48% cycle
efficiency. Their implementation in solar thermal power plants will require solutions to several challenges, including
solar receivers and other components operating at very high pressure and temperature, new heat transfer fluids
for high temperature, and matching power block size to a reasonable solar concentrator field. A second approach is
supercritical CO2 Brayton cycle, offering theoretically cycle efficiency above 50%, but requiring further
development and demonstration of the technology at reasonable scale. Finally, combined cycles (Brayton cycle gas
turbine and Rankine cycle steam turbine) offer the highest cycle efficiency in the range of 55-60%, resulting in
overall solar plant efficiency of around 25-30%, a significant improvement over the current state of the art. Driving
a combined cycle with solar energy requires heating air to over 1,000°C with a solar receiver achieving very high
temperature at high efficiency. So far, high temperature volumetric solar receivers have shown disappointing
receiver efficiency in the range of 70-80%. Approaches to achieve hot air receivers with efficiency exceeding 90%,
and coupling of the receivers to a high-performance combined cycle, will be discussed.
Keywords: Solar Thermal Electricity, Volumetric Receiver, Brayton Cycle, Steam Injection, Combined Cycle
63
Experimental and numerical analysis of Shiraz solar thermal power plant performance during
2009-2011
Ali Rahmatmand, [email protected], Mahmood Yaghoubi, [email protected], Moslem
Raesi, [email protected], Iman Niknia, [email protected], School of Mechanical Engineering /
Shiraz University Shiraz, Iran
Peyman Kanan, [email protected], Renewable energy organization of Iran and School of Mechanical
Engineering / Shiraz University, Shiraz, Iran
Among concentrated solar power (CSP) technologies, parabolic trough technology has been established worldwide
due to its more technical and economical development. In this paper, the performance of current configuration of
Shiraz solar power plant (250kW) is analyzed using the measurements from the field experimental system. The
analysis includes several practical parameters including the oil inlet/outlet temperature of the collectors field,
thermal efficiency, heat losses of the plant components, direct radiation during 2009-2011 and system major
deficiencies regarding installation and operating condition. The performance is found to be in proper agreement
with results of transient simulation data of the plant. The factors that affect low thermal efficiency of collector’s
field such as dust deposition effect and sun tracking effect are explained. Overall thermal performances of the
system, such as superheated steam generation are illustrated and comparison with performance of SEGS plant are
also presented.
Keywords: Parabolic trough collector, solar energy, CSP, thermal efficiency, cycle
Modeling and Simulations of Direct Steam Generation Solar Thermal Power Plant
MSc. Can Uçkun, Assoc. Prof. Dr. Derek Baker, [email protected]
Middle East Technical University, İnönü cad. No:473/B D:2 Karabağlar / İZMİR / TÜRKİYE
In this paper a mathematical model of a parabolic trough solar collector array is presented. Unlike the conventional
parabolic trough collectors of today's commercially available solar thermal power plants, water is the heat transfer
fluid instead of synthetic oil. Using water instead of synthetic oil increases the efficiency of a solar thermal power
plant. Using water as heat transfer fluid does not require any heat exchangers to generate superheated steam.
Simulations are done using water through the absorber of parabolic trough collectors to generate superheated
steam to be used for a steam turbine to generate electricity. Steady state simulation results of a parabolic trough
solar collector array are compared with the published results of INDITEP project and good agreement are found.
With the help of the steady state results that are benchmarked against published data, a complete power plant
simulation is done using mathematical model of a parabolic trough solar collector array and compared with the
published results of the INDITEP project. The simulation study compared with the INDITEP project is then applied to
different locations of Turkey using TMY2 (Typical Meteorological Year 2) weather data files. The results are
analyzed and discussed for availability of solar thermal power plants using direct steam generation with parabolic
trough collectors in Turkey.
Keywords: solar energy; direct steam generation; solar power; parabolic trough
64
Boğaziçi Hall
Air Liquide
Antalya Büyükşehir Bld.
Arıteks
DGS
Enisolar
Etki Atlas
Halk Enerji Bosch
juwi
Motif Proje
NUROL
Oerlikon Solar
Optomek
RA Alternatif Enerji
Schmid
SMA
65
Solar Nokta
Solar Turk
Tekno TIP
TestOne SVCS
Trakya Cam
TÜBİTAK MAM
UFTP
Vaksis
The Scientific and Technological Research Council of Turkey (TUBITAK) is the
public agency in charge of promoting, developing, organizing, conducting and
coordinating research and development in line with the national targets of
economic development and technical progress. Marmara Research Centre
(TUBITAK MAM) is the oldest research organization under TUBITAK. The aim of
TUBITAK MAM is to conduct applied and fundamental research projects
integrated with national and international industrial entities in a customer
focused policy. There exist seven institutes under the frame of TUBITAK MAM
and Energy Institute is one of them.
The Energy Institute (EI) is located in the industrial town of Gebze-Kocaeli near Istanbul, and conducts applied
research on advanced and innovative energy and transportation technologies. It aims to form a bridge
between fundamental research and industrial applications. EI has active research teams on fuel technologies,
gas technologies, combustion, fuel cell technologies and solar energy, power grid technologies, power
electronics, vehicle and battery technologies and wind power.
The EI employs of 220+ researchers,
technicians and staff and net annual expenditure in year 2011 was over €14 Million. Institute has grown out
in recent years and gained significant expertise on design, integration, demonstration and testing of energy
systems and sub systems. EI has collaborated in the following EC FP6/7 projects: EU-DEEP (IP), NATURALHY
(IP), HY-PROSTORE (SSA), BIGPOWER (SSA), MC-WAP (IP), NETBIOCOF (CA), CASES (CA), TERMISOL (STREP),
TyGre (CP), MCFC-CONTEX (CP) and BRISK (CP&CSA) as well as E2PHEST2US (CP).
SOLARTURK is one of the biggest PV module
manufacturer which has 60MW production line
capacity in Turkey. The plant has 15.000m² open and
10.000 m² closed area avaliable with totally completed infrastructure. The company has decided to make an
investment to produce PV module for Turkey and international markets after 3 years of market research. The
invesment decision has been taken under the supervision and Know-How of SCHMID, BOSCH, ABB and some
of the Energy Faculties of some universities The production line will be ready for production till end of
October 2012 and TUV certification will be completed till end of 2012.
The first tender licensed installation volume, 600MW, are planned to be realized in Turkey and also
unlicensed installation (<500KWp) will gain an important role for market especially around eastern and
southeastern anatolia region. Gaziantep city where the company located is the most important and a leading
industrial zone in South East of Turkey and geographically in the center of the estimated possible installation
areas. The city has five Organized Industrial Zones and the average export capacity of these zones was 6
billion USD in the first eight months of the year. Gaziantep city is close to Mersin and Iskenderun ports. Also
highways and railways around the city is very convenient for shipment. Short distance between the city and
middle east countries will be oppurtunity for SOLARTURK. So the location is very convenient to provide
sustainability for the end users and wholesalers with high quality products. As the PV sector grows, capacity
increase and cell production will be our mid term target.
66
Solar Nokta belongs to a company that is in
different businesses for 30 years. Solar Nokta
started its activities at the end of 2011 with the
target of covering all Turkey in the short-term. It
works as an EPC in the solar industry. Its parent
company Akas Energy is the exclusive distribution
and solution partner of Saint-Gobain Solar.
Solar Nokta is together with the customer during whole project life cycle. We start by evaluating the project
and follow all stages of PV installation. All our engineers are experienced, talented and enthusiastic. We
regularly visit big events and fairs to keep updates of the industry.
Solar Nokta perceives its customers as their partners as well as their suppliers. Once a potential customer
becomes our customer, their roofs or lands become our work place. Our offer is to be a reliable partner and
to be available 365days. That’s the reason why we work with the most reliable suppliers in the world.
SCHMID
Branches: Photovoltaic, Printed Circuit Board, Flat
Panel Display
Product Groups and/or About the Company:
Production equipment for Photovoltaics, Printed
Circuit Boards, Flat Panel Displays
Schmid is technologically the world’s leading
supplier of system and process solutions for printed circuitboard technology, flat panel display production as
well as for the photovoltaic industry concerning thin film applications and the manufacture of solar wafers,
cells and modules. The product portfolio comprises single equipment and turnkey production lines with
guaranteed performance parameters such as production capacity and degree of efficiency. The Schmid Group
covers the entire solar value-creation chain with a high percentage of in-house production. The tradition of a
system supplier is already continuing in the fifth generation with the focus on customer-orientated process
solutions, economical concepts and a continuous development of new process technologies in their own
research centers. The Schmid Group produces in Germany, Taiwan, Japan, China and USA and is represented
worldwide with numerous service branches.
67
RA Alternative Energy Ltd. Co.
RA, went into the business in 2011, having the ‘’R&D and Innovation Project Support’’ of KOSGEB (SMEs
Development Organization) for developing an optimization and simulation software for renewable resource
utilization.
Our Main Focus
•
Design and Optimization Software Tool Development
•
Sustainable Energy Action Plans for Local Governments
•
Climate and GHG studies and consultancy
•
Solar Car Projects’ supplier
•
EPCC Consulting
•
Contribution to studies on VOC-EDU.
www.raenerji.com
Demir Enerji was established as consultancy company with team members, who are players of unique and
pioneering international and local projects in the areas of climate change, carbon credit development,
renewable energy, built environment, energy efficiency and energy management. We have a holistic
approach towards our projects incorporating relevant issues - technical, legal, project management, financial,
social and ecological aspects involved.
Demir Enerji offers a wide range of high quality services for multinational corporate, building companies,
industries, private investors, local authorities, NGO`s and energy consumers.
Demir Enerji found the Climate Volunteers to raise awareness about climate change and alter perceptions.
Climate Volunteers has started to work to understand our existence’s impact on environment and climate, to
learn how to measure these impacts, to be able to talk the same metric language with the World, to learn the
measures we can take to decrease our footprint, to be aware of the impacts of different measures, activities
and take action about all these issues. You can reach all this information and calculation-evaluation-offsetting
services on Climate Volunteers’ website.
Some of our selected pioneering project references are as followed:
Sustainable concept development and Project management of BREEAM certification projects. Redevco`s
building projects are the first certified green building projects in Turkey and one of the pilot projects of
BREEAM Europe Scheme.
Development and Registration of Anemon and Mare wind farms under the GS VER registry. These two
projects are the first registered Gold Standard VER projects worldwide.
Consultancy on Carbon footprint and Climate Change strategy of Vodafone Turkey.
Our organization and stuffing features are:
Our four professionals are working on the areas of climate change strategy, carbon credit development,
energy in built environment, renewable energy and energy efficiency.
68
Antalya Metropolitan Municipality
The City of Antalya is located in the south coast on Mediterranean
Sea of Turkey. City is being intersected with sharp travertine
terrace which rises about 40 m vertically above sea level in the
south and parallel laid Taurus Mountains in the north. With
approximately 1.000.000 inhabitants, Antalya is the 6th populous city in Turkey and also most rapidly growing
metropolitan city by a rate of 4% per annum. By its nature made up of dark blue seas, spectacular Taurus
mountains, fervent waterfalls, architectural and multi-denominational religious sites and world known holiday
villages together with the mild climatic conditions, the city is the prime tourist destination in Turkey. The
clean and beautiful beaches of Antalya, where natures colours blue and green unite, is what makes the areas
beaches blue flag. Besides all these natural beauties, the city has a reputation with its international standard
Golf courses and is well on the way in becoming Europe’s biggest golf centre. Tourism dominates the
economic structure of the city, since Antalya is the most popular tourism destination, having a total of about
10 Mio. visitors, the 30% of total international visitors to Turkey in 2010.
Because of the advantage of city’s location and climatic conditions, solar power has always taken a role in
heating for years. Separate systems are being used by inhabitants, especially solar panels on the roof of the
buildings for water heating. This basic system provides energy providence of the households. The Antalya
Metropolitan Municipality has developed a new vision in
city’s solar energy policy since 2009. GÜNEŞKENT – Solar
city – is a main objective of the city to reduce carbon
emission to zero and renewable energy sources. First
step due this policy is a social awareness project called
GÜNEŞEV, a solar friendly complex with living areas and
ecological-agricultural production site has been
completed within this concept. In the light of this policy,
a recreational area called Atatürk Kültür Parkı having
approximately 450.000 m2 area is lightened by energy
saving LED lamps with the energy partly produced by
solar power system which is located in the park area. It is
planned to implement this project in all the recreational areas within the Metropolitan Municipality. The
Metropolitan Municipality intends to use LED system in traffic signals with the energy produced by solar
power.
69
Çataklı Enerji is the partner of DGS ( German solar association sec. Berlin-Brandenburg ), VALENTIN
SOFTWARE ( PV SOL ), SOLMETRIC ( SUNEYE ) and LEXSOLAR.
Our focus is on the education of people who want to work in the photovoltaic business. For this we translated
the educational book published by DGS “ Photovoltaik Systeme” from German into turkisch. Every month we
provide a 3 day basic training in Istanbul and Ankara and a 5 day technique training in Istanbul. Attendants are
getting a DGS Certificate after passing the exam.
Also we are providing training and customer service for VALENTIN SOFTWARE ´s PV SOL and SOLMETRIC
SunEye shadowing measurement system.
LEXSOLAR is providing educational training sets for renewables. We do the sales and trainings for this
equipment. Çataklı Enerji is also giving consulting service for turn key PV FAB´s and expertise services for you
PV-Projects.
For more information please visit our webpage: www.catakli-enerji.com
or sent us a mail to [email protected]
Motif Project Ltd. Şti.
Established in 1995 still in collaboration with the
universities and organizations at national and
international levels, improves the opportunities
for researchers, specialists, engineer and technical staff by preparing courses, holding international
symposiums, organizing panels and seminars, publishing books, guides and scientific papers for the success of
pv in Turkish Market.
Photovoltaic Actions
Design, modelling, test and comparative performance analyses of PV electricity generators with different
topologies.
Areas of Interest, Grid connected PV power systems
Off-grid PV power systems, Hybrid power systems
PV test and power plants
PV monitoring
70
OPTOMEK Optical Mechanical Engineering Industry and Trade Ltd. Co.
Optomek olarak temel hedefimiz ileri teknoloji
ürünlerinin Türkiye'ye kazandırılması ve
üretilmesidir. Bu ilke doğrultusunda savunma
sanayi, kamu kuruluşları ve özel sektöre makine
ve malzeme tedarik etmekte, ileri
teknoloji ürünlerinin satışını yapmakta ve satış sonrası teknik desteğini vermektedir.
Şirketin faaliyetleri; sivil ve askeri amaçlı sistemlerin optik ve opto-mekanik tasarım, üretim ve eğitimleri, optik
sistem elemanlarının tedariki, elektro-optik sistemlerin ve yedek parçalarının satış ve servisi, CNC mercek
üretim tezgahları, göz içi lens ve optik laboratuar ekipmanlarının satış temsilciliği, teknik servis ve
danışmanlığıdır.
71
Visual Presentations, Executive Lounge Hall
Mustafa ÖZTAŞ
Yalova University, TURKEY
Efficiency Characteristics of Photovoltaic Panel in Gaziantep, Turkey
In this work, we were investigated the analysis of the system performance, evaluation of the system efficiency and
power output, taking into account the weather conditions. As a part of certain design compromises,that took into
account,aesthetic,safety,and cost considerations,non-optimal tilt angles and occasional shading of the PV modules
made the efficiency of PV system lower than the peak rating of the cells.The yearly average efficiency of the
sunshade solar panel is 12.7%(average over 27.6 oC surface temperature),with a minimum of 4.2%(average over
12.6 oC surface temperature)in January and a maximum of 20.4%(average over 45.2 oC surface temperature)in
July.
Şule Ela ERTAN
Ege University Solar Energy Institute, TURKEY
Nanostructured ZnO Photoelectrodes for Dye Sensitized Solar Cells
Nanostructured ZnO Photoelectrodes for Dye Sensitized Solar Cells Hızır SARICA, Sule ERTEN-ELA Ege University,
Solar Energy Institute, 35100 Bornova-Izmir/ TURKEY Zinc oxide, an n-type semiconductor with wide band gap of
3.3 eV, has attracted vast research interests because of its tremendous potential applications in piezoelectric
nanogenerators, nanolasers, solar cells, gas sensors and so on [1–5]. The synthesis of one-dimensional (1-D) nanoor microstructured ZnO semiconductor materials has attracted considerable research activity because of their great
potential for fundamental studies of the roles of dimensionality and size in their physical properties as well as for
applications in optoelectronic devices and functional materials [6]. ZnO nanomaterials with 1-D structures, such as
nanowires or nanorods, are especially attractive due to their tunable electronic and optoelectronic properties, and
the potential applications in the nanoscale electronic and optoelectronic devices [7]. Recently, ZnO nanocrystals
with various shapes have been synthesized using different surfactants [8-9]. In this paper, different nanostructured
ZnO nanorods are prepared for dye sensitized solar cell application. Nonoflower-type ZnO nanorods, butterfly-type
ZnO nanorods and ZnO nanoarrays are synthesized using solution-phase reactions. Also calcination effects on the
morphology at low temperature are discussed. The as-prepared and calcined ZnO crystallites are characterized by
X-ray diffraction (XRD), Scanning electron microscopy (SEM) measurements. References [1] S. Erten-Ela, S. Cogal, S.
Icli , Inorganica Chimica Acta, 362 (2009) 1855. [2] S. Erten-Ela, S. Cogal, G. Turkmen, S. Icli, Current Applied
Physics,10 (2010)187S. [3] S. Erten-Ela, A.C. Cakir, Energy Sources, Part A, 2011 in press. [4] Erten-Ela, J. Brendel, M.
Thelakkat, Chemical Physics Letters, 510 (2011) 93. [5] a)S. Erten-Ela, M.D. Yilmaz, B. Icli, Y. Dede., S. Icli, and E.U.
Akkaya, Organic Letters, 10 (2008) 3299. [6] S. Kolemen, A. Bozdemir, Y. Cakmak, G. Barin, S. Erten-Ela, M.
Marszalek, J-H. Yum, S. M. Zakeeruddin, Md. K. Nazeeruddin, M. Graetzel and E. U. Akkaya, Optimization of
Distyryl-Bodipy Chromophores for Efficient-Panchromatic Sensitization in Dye Sensitized Solar Cells, Chemical
Science, 2, (2011), 949. [7] S. Kolemen, Y. Cakmak, S. Erten-Ela, Y. Altay, J. Brendel, M. Thelakkat and E.U. Akkaya,
Solid-State Dye-Sensitized Solar Cells Using Red and Near-IR Absorbing Bodipy Sensitizers, Organic Letters,12 (2010)
3812. [8] B. Liu, H.C. Zeng, J. Am. Chem. Soc. 125 (2003)4430. [9] Y. Hu, T. Mei, J. Guo, T. White, Inorg. Chem, 46
(2007) 11031.
72
Şule Ela ERTAN
Ege University Solar Energy Institute, TURKEY
Photovoltaic Performance of Nanostructured TiO2 Layers
Photovoltaic Performance of Nanostructured TiO2 Layers in Dye Sensitized Solar Cells Sule ERTEN-ELA Ege
University, Solar Energy Institute, 35100 Bornova-Izmir/ TURKEY Dye sensitized solar cells are typically composed of
an electron transporting inorganic semiconductor material and a sensitizer material [1, 2]. A sensitizer, as the lightharvesting component in a dye-sensitized solar cell (DSSC), is of paramount importance to photovoltaic
performance. The sensitizer is attached to the surface of a mesoporous wide band-gap semiconductor serving as
electron transporter [3, 4]. The interest in metal free, organic dyes with high extinction coefficients has grown in
recent years for organic solar cell research.. In order to investigate organic dyes and, in the longer run, prepare an
efficient solar cell dye, a number of different organic dyes were designed and synthesized [5-7]. In this study, we
report the effect of TiO2 thickness dependence study using metal-free organic sensitized solar cells. The sensitizer
have been used to manufacture solar cell devices to explore current-voltage characteristics by using different
thicknesses of TiO2 layers. The sensitizer exhibits a remarkable efficiency using nanocrystalline 10 + 4 μm TiO2
layers. References [1] O’Regan B, Graetzel M, (1991) Nature 353:737 [2] Qin H, Wenger S, Xu M, Gao F, Jing X,
Wang P, Zakeeruddin S.M, Graetzel M, (2008) J. Am. Chem. Soc. 130:9202 [3] Kolemen S, Bozdemir A, Cakmak Y,
Barin G, Erten-Ela S, Marszalek M, Yum J-H, Zakeeruddin S.M., Nazeeruddin M.K, Graetzel M, and Akkaya E.U (2011)
Chemical Science, 2:949 [4] a) Erten-Ela S, Marszalek M et al (2010), Curr. App. Phys 10:749 b) Erten-Ela S, Cogal S,
et al (2010) Curr. App. Phys.10:187 [5] Erten-Ela, J. Brendel, M. Thelakkat, Chemical Physics Letters, 510 (2011) 93.
[6] a)S. Erten-Ela, M.D. Yilmaz, B. Icli, Y. Dede., S. Icli, and E.U. Akkaya, Organic Letters, 10 (2008) 3299. [7] S.
Kolemen, Y. Cakmak, S. Erten-Ela, Y. Altay, J. Brendel, M. Thelakkat and E.U. Akkaya, Solid-State Dye-Sensitized
Solar Cells Using Red and Near-IR Absorbing Bodipy Sensitizers, Organic Letters,12 (2010) 3812.
Nesrin TÖRE
Gebze Institute of Technology (GYTE) - National Metrology Institute (TUBITAK UME), TURKEY
Effect of Blend Ratio On Poly (PPE)-Alt-Poly(PPV) Polymer Solar Cell
We investigated the effect of the amount of phenyl C61 butyric acid methyl ester (PCBM) on anthracene-containing
poly(p-phenylene-ethynylene)-alt-poly(p-phenylene-vinylene) (PPE–PPV) polymer (AnE-PVstat) solar cells. The
efficiencies and fill factors of the polymer solar cells improved with increasing PCBM content. The highest efficiency
obtained was 2.13% for AnE-PVstat:PCBM solar cells with 75% PCBM content. The increased efficiency for that
PCBM content can be attributed to a change in the thin film nanostructure. The normalized efficiency values versus
time plot from ISOS-L-1 test indicated that the AnE-PVstat:PCBM solar cell with 1:2 blend ratio showed 100%
durability; for 1:3 and 1:4 ratios it showed with approximately 96% durability under standard solar irradiation of
100 mW/ cm2 (AM1.5G) at ambient conditions for 21 h. ISOS-D-3 Damp test indicated that the normalized jsc and
normalized efficiency versus time graphs showed similar behaviors; the AnE-PVstat:PCBM solar cell with 1:4 ratio
has 99% durability for 40 h in a weathering chamber.
73
Emre MÜLAZİMOĞLU
Middle East Technical University (METU), TURKEY
Silver Nanoparticle Decorated Silicon Nanowires for Solar Cells
In this study, different routes for the decoration of silver (Ag) nanoparticles onto silicon nanowires (Si NWs) have
been investigated for plasmonic applications. It has been long known that metallic nanoparticles (i.e. Au, Ag, Cu)
start to oscillate and resonate under electromagnetic radiation, while size and shape of the nanoparticles can be
used to tune this resonance. Firstly; vertical arrays of Si NWs with different lengths have been fabricated by
electroless etching method. Incorporation of Ag nanoparticles has been done by two alternative routes. In the first
vacuum based method, Ag is evaporated onto Si NWs, while the subsequent annealing resulted in the formation of
nanoparticles through thin film dewetting. The effects of annealing time, temperature and film thickness have been
investigated. The optimized parameters have been used to build a radial heterojunction solar cell through the
deposition of p-type polymer as a complementary layer onto the silver nanoparticle decorated silicon nanowires.
Solar cell characteristics have been measured.
Halil İbrahim YAVUZ
Middle East Technical University (METU), TURKEY
Improvement of Photovoltaic Efficiency on Dye-Sensitized Solar Cells (DSSC) by Zr Based Cation
Modified Layers
Improvement of photovoltaic efficiency on dye-sensitized solar cells (DSSC) by Zr based cation modified layers Halil
İbrahim Yavuz*,**, Macit Özenbaş*,** *Middle East Technical University, Metallurgical and Materials Engineering
Department, 06800, Ankara, Turkey **GUNAM (Center for Solar Energy Research and Applications), Middle East
Technical University, 06800, Ankara, Turkey Although the TiO2 layer generally used in dye-sensitized solar cells is
functioning as absorber layer, scattering layer and blocking layer, the idea of replacing these layers by others is a
new study. Due to TiO2 anatase nano structure, electrons cannot easily reach the electrode surface; instead they
accumulate on TiO2 surface. This is the reason of limited efficiency obtained for TiO2 structures. Therefore, Zr+4
doped TiO2 layers have been realized on FTO glass substrates by sol-gel and hydrothermal technique to overcome
these difficulties. These were used for the production of nano-crystalline dye-sensitized solar cells (nc-DSSC). The
effects of cation modification on each part of the anode layer in DSSC were investigated. Several models of Zr
cation modified DSSC were explained. For the UV action spectra of unsensitized photochemical cell, the mixed
single zirconia/titania electrode can absorb UV light below 380 nm, corresponding to band gap (Eg) around 3.27 eV,
which is higher than that of pure titania. This result contributed to the improvements on short-circuit photocurrent
up to 58%, open-circuit voltage up to 4%, and solar energy conversion efficiency up to 4 times than that of pure
titania obtained by sol-gel technique. The cell prepared by 5 μm thick mixed Zr modified TiO2 single electrode
yielded short-circuit photocurrent about 14 mA/cm2, open-circuit voltage about 600 mV and the conversion
efficiency of 4.2%. According to multi layers system resources (composed of blocking layer, absorber layer,
scattering layer), using of different Zr modified TiO2 layers improve efficiency up to 5.86% while commercial DSSC is
5.01 %. The DSSC composed of Zr Modifed layers (Mod-Zr DSSC)has higher Jsc and Voc (17.5 mA/cm2 and 0.76V)
than DSSC, which is composed commercial paste (16.8 mA/cm2 and 0.70V). On the light of studies, Zr cation
modification can be candidate a solution of the reason of limited efficiency obtained for TiO2 structures. Keywords:
Zirconium oxide , titanium dioxide, sol-gel, nano composite, DSSC.
74
Vedat KIRAY
Turgut Ozal University, TURKEY
Determining the hardware features and automation criteria of a system enabling the usage of solar
panels in apartment complexes
In this study, hardware features and automation criteria of solar energy panels are determined which enables them
to be used in apartment complexes together and efficiently by the tenants. These criteria are used in generating
the algorithm of the automation. Both the relationship of the system with the central grid and the energy system in
the complex are considered when determining the automation criteria. Additionally, common budget management
of the complex is included in the automation. As a result of the lack of space on the roofs of the complexes, tenants
not being able to act individually and place panels on the roofs, thus not being able to take advantage of solar
energy, is the problem leading to this research at hand. The study shows that not only the people living in isolated
houses but also the tenants of the apartment complexes can benefit from solar energy, use a clean type of energy
supporting the protection of the environment and pay less for a quality energy. The developed system is designed
as a microgrid compatible with smart grids structure and the gains to be realized as a result of the relief on the
energy transmission and distribution lines with the dissemination of the solar panels on the apartment complexes
is also pointed out in the study. The study is conducted considering the apartment complex structure widely used in
Turkey.
İdris CANDAN
Middle East Technical University (METU), TURKEY
Effect of In/Ga Ratio on The Properties of CuIn1-xGaxSe2 (CIGS) Thin Films
Effect of In/Ga Ratio on The Properties of CuIn1-xGaxSe2 (CIGS) Thin Films İdris Candan, Hasan Hüseyin Güllü, Özge
Bayraklı, Mehmet Parlak and Çiğdem Erçelebi Middle East Technical University, Department of Physics, 06531,
Ankara, Turkey The Center for Solar Energy Research and Applications (GÜNAM), METU, Ankara, Turkey In this
work, CuIn1-xGaxSe2 (CIGS) thin films were deposited by sputtering technique from Cu, InSe and GaSe targets. For
all the samples, soda lime glass substrate was used and growth temperature was kept 300oC. The effect of In/Ga
ratio of the thin film samples have been investigated via controlling Ga concentration over the range 0<x<1. The
structural properties of deposited films have been studied by using X-ray diffraction (XRD) technique. Structural
variations of CIGS thin films depending on changing Ga content have been investigated by using XRD
measurements. Lattice parameters a and c of all films were computed from these measurements. The surface
morphologies and compositions of samples have been investigated by scanning electron microscopy (SEM) and
energy dispersive X-ray diffraction analysis (EDXA) systems, respectively. Electrical properties of materials were
determined from temperature dependent conductivity and photoconductivity in between 100 and 400 K. Hall
effect measurements were also performed for mobility and carrier concentration at room temperature. For optical
properties of deposited semiconductor CIGS thin films were studied by means of transmission measurements,
optical band gaps of CIGS samples were calculated from these measurements. Spectral photoresponse
measurements were also carried out.
75
Caner DURUCAN
Middle East Technical University (METU), TURKEY
Transparent conductive oxide (TCO) thin films elaborated by modified sol-gel processing
Sputtering has been widely employed in obtaining high quality ITO films. Sophisticated processing conditions and
inefficient use of raw materials however are intrinsic processing limitations for sputtering. Solution-based
processing offers simple/effective method for forming ITO films. In this work, ITO films were formed on SLS glass by
modified sol-gel route(s). ITO sols were prepared using indium- and tin salts stabilized in organic solvents and
addition of oxalic acid dihydrate (OAD). The effect of OAD on microstructural, morphological, electrical and optical
properties of the films were investigated and compared with the performance properties of unmodified sol-gel ITO
films. The amount of OAD, film thickness, and calcination temperature on electrical/optical properties of ITO films
were reported. It was shown that film formation efficiency and homogeneity was enhanced with OAD addition. ITO
films exhibiting high transparency (≈ 98 %, visible region) with a sheet resistance as low as 3.8 kOhm/sqr have been
formed.
Syed Zaid Hasany
Middle East Technical University, Northern Cyprus Campus, TURKEY
Solar Thermal Electric System Modeling and Annual Performance Simulation for Cyprus
Limited fossil resources and severe environmental problems require new sustainable electricity generation options
that not only utilize renewable means but are also economically feasible. In geographies with rich solar resources,
like Cyprus, concentrating solar power (CSP) can be utilized for sustainable and economical electricity generation.
The aim of this paper is to develop a model for the Solar Thermal Electric (STE) system comprising of Parabolic
Trough Collectors (PTC), electricity demand, an auxiliary energy resource (propane fired boiler), Organic Rankine
Cycle (ORC) and wet cooling tower at Middle East Technical University-Northern Cyprus Campus (METU-NCC). To
quantify the environmental impacts of the system the performance metrics such as CO2 emissions and water
consumption by the systems are defined. An analysis is also carried out by extending the solar field in order to
eliminate the dependence of the existing system on fossil fuel. Economic analyses of the existing system and the
proposed system is evaluated. The cost of the electricity from both systems is estimated with and without
externality due to CO2 emissions and a comparison is made between the cost of electricity generation from the
systems and grid electricity. The payback periods of the current and proposed STE systems are also calculated. For
the modeling of the STE system Direct Normal Insolation (DNI) on 1-axis East-West tracking surfaces are quantified
for Cyprus. Hourly meteorological weather data derived from a TMY2 formatted file for Larnaca, Cyprus, for an
entire year is used for solar resource assessment. It is found from the economic analysis that the price of the
electricity from the extended STE system is higher than the existing system and the grid tariff. However future
environmental regulations on the CO2 emissions may significantly alter the choice among the options on an
economical basis.
76
Nalan Çiçek BEZİR
Department of Physics, Faculty of Art and Science, Süleyman Demirel University, 32260 Isparta, Turkey
The Applicability Of Tio2/Azo Dye Composite Particles For A Dye-Sensitized Solar Cell
Nalan Çiçek Bezir1,Murat Kaleli1, Atilla Evcin2, Fatma Karipcin3, Ayşe Oktay1,Gülten Onay1 1Süleyman Demirel
Üniversitesi, Fizik Bölümü, Isparta Türkiye 3AfyonKocatepe Üniversitesi, Malzeme Mühendisliği Bölümü, Afyon
Türkiye 3Niğde Üniversitesi, Fizik Bölümü, Niğde Türkiye In this study photovoltaic properties of new azo (4-(2pyridylazo)resorcinol and 4-(2-thiazolyazo) resorcinol ) organic dyes for dye sensitized solar cells (DSSC) were
investigated. DSSC structure consist of a nanocrystalline TiO2 thin-film layer sandwiched between an ITO (indium
tin oxide) substrate and a thin layer of TiO2/dye composite particles. After the preperation of working electrode
according to the description above, counter electrode was formed by coating platinum conductive over ITO
substrate. Liquid electrolyte, iodine (I2) and potassium iodine (KI), was injected into the cell through a hole on the
cell that was prepared in advance.
Pantea AURANG
Middle East Technical University (METU), TURKEY
Optical and Passivation Properties of ZnO Nanowires as Antireflective Coatings for Industrial Scale
Single Crystalline Silicon Solar Cells
In this work, both planar and textured industrial scale (156mm × 156mm) single crystalline silicon solar cells have
been fabricated using zinc oxide (ZnO) nanowires as antireflection coating (ARC). ZnO nanowires were grown in a
few minutes via hydrothermal method within a commercially available microwave oven. Surface passivation
property of such an ARC layer has been investigated as well as its optical properties. Relative improvement in
excess of 65 % in the reflectivity was observed for both planar and textured Si surfaces. Effective lifetime (teff)
measurements were presented. With growth of ZnO nanowires, teff increased from 9 µs to 71 µs with the carrier
injection level of 1015 (10 to the power of 15) cm-3 . Increased carrier lifetime revealed the passivation action of
the ZnO nanowires in addition to their ARC property. 25% and 14% enhancement in the photovoltaic conversion
efficiency was obtained in planar and textured single crystalline solar cells, respectively. Our results reveal the
potential of ZnO nanowires as ARC that can be deposited through simple solution based methods and the method
investigated herein can be simply adapted to industrial scale fabrication.
Tuğrul MARAL
Middle East Technical University (METU), TURKEY
Increasing the performance of multirow PV or thermal flat plate collectors with tilted reflectors
It is possible to increase the radiation incident on an absorber by use of planar reflectors. Previous study, horizontal
reflector was put in front of tilted collector, in order to reflect the solar insolation on tilted collector. Shading
occurs and its calculations are needed when flat plate collectors are arranged in rows. In this study, a reflector
between the top of the front row and bottom of back row has been put and its performance is evaluated in order
to prevent several malfunctions caused by shading in photovoltaics.
77
Serhat ŞENSOY, İzzet BALTA, Alper AKÇAKAYA, Hayreddin BACANLI, Christine Träger-CHATTERJEE
Turkish State Meteorological Service, TURKEY
Comparison of Satellite and Surface Radiation Data in Turkey for the Year 2006
In this study, CM-SAF remote sensing SIS (Surface Incoming Solar Radiation) and Turkish in-situ surface radiation
data have been compared for Turkey for the year 2006. According to sunshine duration and radiation data
measured by TSMS from 1971 to 2000, Turkey's annual mean total sunshine hours are 2573 (daily mean is 7h) and
mean total radiation is 1474 KWh/m²-year (daily 4 KWh/m²). CM-SAF SIS products of the year 2006 have been
extracted by using the IDL based CM-SAF GUI available from the CM SAF webpage. Surface radiation data unit was
cal/cm²/day and CM-SAF SIS data unit was W/m². These two units have been converted to KWh/m². Geographic
variables are measured at certain points, and prediction map for the entire area is been obtained by Inverse
Distance Weighted (IDW) spatial interpolation method. Data have been designed and calculated by using Excel.
ArcGIS 9.3 is used for spatial interpolation, raster calculation and mapping activities. According to residual map, in
the western part of the country CM-SAF SIS values are greater than in-situ observation while mountainous eastern
part and around Afyon, Burdur, Cankırı, Kayseri, Nigde and Karaman CM SAF SIS values are smaller. Correlation
coefficient has been found as 0.71 between two series.
Şahin COŞKUN
Middle East Technical University (METU), TURKEY
Silver Nanowire Networks And Their Utilization In Organic Photovoltaics
Transparent conductors are one of the main components of organic photovoltaics. They serve as both transparent
windows for sunlight to reach photoactive layer and charge collector. The most widely used transparent conductor
is indium tin oxide (ITO). Recently, some concerns rose about ITO and other alternatives have been investigated.
Random networks of silver nanowires are promising candidates for transparent conductor applications. In this
study, silver nanowires were aimed to be used instead of ITO in organic solar cells. For this purpose silver
nanowires were synthesized through solution based polyol process. Following purification, they were coated onto
substrates via spray coating. Then, an additional annealing process was applied to decrease sheet resistance of
silver nanowire networks. As hole transport layer PEDOT:PSS was spin coated onto silver nanowires networks.
P3HT:PCBM mixture was also spin coated as photoactive layer. Finally, aluminum back contact was evaporated as
cathode. Parameters effecting transparent conductors characteristics of silver nanowires and solar cell properties
will be presented.
78
Hasan Mert BOZACI
Middle East Technical University (METU), TURKEY
Terahertz Study Of Excitations In Semiconductors
Renewable energy technologies are some of the most important research areas of the 21st century. Solar cells are
rapidly developing to meet the demands of consumers. Thorough analysis of their fundamentals and functionality
is, therefore of rising interest. To meet this end, development of a solar cell terahertz imaging system is discussed
and investigated in this paper. Interaction of the terahertz (t-ray) radiation with free-carriers in bulk
semiconductors, as well as variation of the extracted parameters by the photoexcitation of the bulk, is analysed.
Various types such as a-Si, poly-Si, mono-Si and SiN coated materials are optically investigated with terahertz TimeDomain transmission Spectroscopy (THz-TDS), to find out their electrical properties. Since metal contacts would
reflect THz radiation, transmission setup would not work after the implementation of metal contacts; A reflection
setup is proposed for investigation of PV devices, namely their electrical properties and their variation after
photoexcitation in time domain. Possibility of frequency-dependent imaging of solar cell devices are also
investigated.
Şule Ela ERTAN
Ege University Solar Energy Institute, TURKEY
Optical and morphological properties of nanocomposit metal oxide thin films for dye sensitized solar
cell application
Optical and morphological properties of nanocomposit metal oxide thin films for dye sensitized solar cell
application Hızır SARICA, Sule ERTEN-ELA Ege University, Solar Energy Institute, 35100 Bornova-Izmir/ TURKEY In
recent years, transparent conductive oxides (TCOs) have attracted much attention owing to their potential
applications in electronics and photovoltaic devices [1]. CdO is one of the most important TCO materials; it is an ntype semiconductor and has a direct band gap of 2.2 eV at 300K. It has many attractive properties such as high
optical transmittance and low resistivity. CdO films have been used widely in many applications such as
photodiodes, solar cells, phototransistors, and gas sensors. Many methods have been adopted to grow CdO films
such as MOCVD , sol–gel , and reactive evaporation [2]. Zinc oxide, an n-type semiconductor with wide band gap of
3.3 eV, has attracted vast research interests because of its tremendous potential applications in piezoelectric
nanogenerators, nanolasers, solar cells, gas sensors and so on [3-7]. In this study, nanostructured CdO and ZnO thin
films are prepared by wet chemical process. Their optical and morphological properties are investigated. And then,
different ratio of ZnO/CdO nanocomposit thin films are prepared and their optical and morphological properties
also studied for dye sensitized solar cells. nanostructured ZnO nanorods are prepared for dye sensitized solar cell
application using UV-vis spectrophometer, atomic force microscopy (AFM) and scanning electron microscopy
(SEM). References [1] D.R. Kammler, T.O. Mason, K.R. Poeppelmeier, J. Am. Ceram. Soc. 84 (2002) 1004. [2] M.
Ortega, G. Santana, A. M-Acevedo, Solid state Electron 44 (2000) 1765. S. Erten-Ela, S. Cogal, S. Icli , Inorganica
Chimica Acta, 362 (2009) 1855. [3] S. Erten-Ela, S. Cogal, G. Turkmen, S. Icli, Current Applied Physics,10 (2010)187S.
[4] S. Erten-Ela, A.C. Cakir, Energy Sources, Part A, 2011 in press. [5] Erten-Ela, J. Brendel, M. Thelakkat, Chemical
Physics Letters, 510 (2011) 93. [6] a)S. Erten-Ela, M.D. Yilmaz, B. Icli, Y. Dede., S. Icli, and E.U. Akkaya, Organic
Letters, 10 (2008) 3299. [7] S. Kolemen, A. Bozdemir, Y. Cakmak, G. Barin, S. Erten-Ela, M. Marszalek, J-H. Yum, S.
M. Zakeeruddin, Md. K. Nazeeruddin, M. Graetzel and E. U. Akkaya, Optimization of Distyryl-Bodipy Chromophores
for Efficient-Panchromatic Sensitization in Dye Sensitized Solar Cells, Chemical Science, 2, (2011), 949.
79
Nurdan Demirci ŞANKIR
TOBB University of Economics and Technology, TURKEY
Effect of Solution Stoichiometry on the Film Properties of CuInS2 Absorber Layers Deposited by
Ultrasonic Spray Pyrolysis Technique
Solution based manufacturing methods not only enable the very large area applications but also made it possible to
atmospheric condition manufacturing. In other words, equipment cost of these methods is much lower compare to
the vacuum based techniques. Hence, solution based methods have been gaining more attention especially for the
thin film solar cell applications. In this study, ultrasonic spray pyrolysis (USP) technique has been used to deposit
copper indium disulfide (CuInS2), which is one of the I-III-VI2 chalcopyrite-type mixed crystal semiconductor having
direct band gap around 1.5 eV and high absorption coefficient. Therefore, it is possible to produce highly efficient
thin film solar cells using this absorber layer. Basically in USP, solution containing the precursor material is fed
through the nozzle using a syringe pump. Solution, ultrasonically atomized in the nozzle, is transported on a preheated substrate where the precursors are decomposed and form thin films. Film formation and the properties
strongly depend on the manufacturing conditions such as substrate temperature, infuse rate and the type of
solvent. Stoichiometry of the films can be controlled by changing the molar ratios of the starting materials in the
solution. Here the In/Cu and S/In molar ratios in the precursor solution have been changed to obtain the
stoichiometric CuInS2 films. First, In/Cu ratio was changed from 0.30 to 0.90 while keeping the S molarities
constant at 10 mM. For higher In/Cu ratios films did not adhere to the surface. SEM analysis confirmed that
pyramid like crystals formed on the surface for 0.3 and 0.45 In/Cu ratios. When the In/Cu ratio increased, pyramid
like structures turned into the spherical agglomerations on the surface. Finally, very smooth surfaces have been
observed for the 0.9 In/Cu ratio. Thickness of the films was ranging between 1.04 and 1.85 μm depending on the
In/Cu ratio. The thickest films were obtained for the 0.60 In/Cu ratio for which the large agglomerates have been
observed on the surface. Chemical composition of the films has been determined by the Energy Dispersive X-Ray
Analysis (EDAX) at 15 kV accelerating voltage. As expected when the In amount increased in the precursor solution
the atomic percent of In in the films also increased. The most stoichiometric films have been observed for the 0.9
In/Cu ratio which was 1.03/1.00/1.98. However, 3.67 and 5.67 atomic percent chloride contamination has been
observed for the 0.75 and 0.90 In/Cu ratios, respectively. XRD analysis proved that all samples have the typical
chalcopyrite CuInS2 diffraction peaks. As a general trend, crystallite size decreased with increasing the In molarity
in the precursor solution. Optical band gap (Eg) values of the sprayed CuInS2 films were calculated from the (αhv)2
versus photon energy plots. Eg of the films increased from 1.3 to 1.41 eV while the In/Cu ratio was ranging
between 0.30 and 0.90.
Hardar AKDAĞ, Saliha ÖZDEMİR, Armağan KINAL, Canan VARLIKLI, Siddik İÇLİ
Ege University Solar Energy Institute, TURKEY
Imidazole attached 1,8-naphthalene monoimide structures for photonic applications
In this study, the synthetic details of N-(5-penthylimidazole)-1,8-naphthalene monoimide (NIIM5), 5-methoxy,
penthyl-1,8-naphthalene monoimide (NI5OMe),
N-propyl-1,8 naphthalene monoimide (NIC3) and N-(3propylimidazole)-1,8-naphthalene monoimide (NIIM3) are presented. Their photophysical and electrochemical
properties are studied by utilizing UV-Vis, Fluorescence Spectroscopy and Cyclic Voltammetry. The DFT and TD-DFT
calculations (B3LYP/6-31G(d) level of theory) were performed to determine the stable geometries, excitation and
HOMO-LUMO energies for the studied molecules. Electron donating abilities of the imidazole ring to the naphthyl
imide structure are discussed for their potential to be used in some of the photonic applications.
80
Ben Slama ROMDHANE
ISSAT Gabes Tunisia, TUNISIA
Hydrogen production by water electrolysis Effects of the electrodes materials nature on the solar
water electrolysis performances
Our contribution in the production of hydrogen, vector of energy, consists in testing the water electrolysis by
photovoltaic solar energy. The realization of some electrolysers whose electrodes are made in various materials,
showed a clear difference from the point of view produced hydrogen flow, conversion efficiency, specific energy
consumption and the electrodes lifespan. This made it possible to classify materials, by performances descending
order, as follows: copper, lead, bronzes, aluminum, stainless, graphite and steel. However lead has a too low flow
and aluminum corrodes quickly. Steel admits poor yield and lifespan. Then, we retain primarily copper like anode
metal. To increase the hydrogen produced flow by electrolysis, the electrolysers parallel assembly choice is
essential. According to the hour of the day, the parameters evolution: consumed power, efficiency, and specific
energy consumed differ from a material with another, which is explained by the fact why the power supply of solar
origin, is variable in the day course.
Rüştü EKE, Ali ŞENTÜRK, Şener OKTİK
Mugla Sıtkı Kocman University, TURKEY
Electricity Yıield Of Grid Connected Photovoltaic Systems Installed At Mugla Sıtkı Kocman University
The Mugla Sıtkı Kocman University Clean Energy Research and Development Centre, established in 1996, is
currently one of the leading research and technology development centers in the field of photovoltaics. Mugla Sıtkı
Kocman University is the largest photovoltaic park in Turkey consisting of 110kWp photovoltaic power systems
(PVPS) demonstrations in the Main Campus. 91.6kWp (83%) of PVPS is grid connected where the rest are
standalone applications. The first grid connected PV systems are installed in 2001 on the top of the Mentese Library
of Mugla Sıtkı Kocman University. The other grid connected applications are on the roof of Turkevi Student
Cafeteria, on the façade and towers of the Staff’s block of the Building of Education Faculty and two tracking
systems which are installed in 2003, 2008 and 2009, respectively. All PV systems are financially supported by DPT
(State Planning Organization) and (BAP) Scientific Research Council of Mugla Sıtkı Kocman University. This paper
summarizes the electricity yield and the performance of grid connected PV systems after their installation. The
total electricity fed into University grid is about 480MWh for 11 years between May 2001 and December 2011
where the first PV system with 10 kWp rated power is installed only.
81
Mehmet Ali OLĞAR, Lutfi OZYÜZER, Şebnem YAZICI, Ekrem YANMAZ, Gülnur Aygun ÖZYÜZ, Ayten
CANTAŞ, Metin KURT
Karadeniz Technical University, TURKEY
Deposition and Sulfurization Processes of CZTS Absorber Layer on Ti and Mo Coated SLG for Solar Cells
The thin film solar cell technologies receive increasing interest from the photovoltaic industry because of their
potential producing low cost electricity compared to wafer based crystalline Si technologies. Although CIS and CIGS
such some important absorber layers and have maximum efficiencies approaching %20 [1], they contain rare and
expensive materials like In, Ga, Te and also include toxic elements like Cd and Se that represent disadvantages.
Cu2ZnSnS4 (CZTS) can be good choice for new absorber layer in terms of presenting absorption coefficient over 104 cm-1 and band gap energy near 1.45 eV [2]. Unlike the others, CZTS thin films are one of the most viable
materials which contain earth abundant elements for low cost and less toxic elements for the environment. In this
study, we fabricate CZTS absorber layer with dc magnetron sputtering in-situ growth by two steps. The first step is
sequential metallic precursor deposition layer by layer on Mo and Ti coated soda lime glass (SLG). We optimize the
order and thickness of each layer, Cu, Zn and Sn. Due to the matching thermal expansion coefficient of titanium
with CZTS, we deposited Ti on SLG substrate as a back contact layer. By this way, we can compare advantages and
disadvantages of the new back contact Ti and traditional back contact Mo. These layers are then heated up in a
Sulphur (S) + Argon (Ar) atmosphere. Then we find the optimum method and temperature for sulfurization process.
The datails of the fabrication process will be discussed. *This research is partially supported by TUBİTAK project
with number 112T068. References [1] I. Repins et al., Prog. in Photovolt.: Research and Applications 16, 235–239
(2008). [2] J.M. Raulot et al., J Phys Chem Solids 66, 2019–2023 (2005). [3] H. Araki et al., Thin Solid Films 517,
1457-1460 (2008).
Koray KARA, Bircan DİNDAR
Ege University Solar Energy Institute, TURKEY
Characterization Of Organic Field Effect Transistors With Phthalocyanine Doped Active Layers
In this study active layers of organic field efffect transistors have been doped with various metal phthalocyanines to
increase the mobility of devices and their electrical parameters have been characterized .
For this study three
new phthalocyanine cores have been synthesized in our institute. Zinc and cobalt have been used as center atom
with each phthalocyanine core to obtain six different phthalocyanine complexes. These phthalocyanine cores are
2(3),9(10),16(17),23(24)-tetra(4-((2,4,4-trimethylpentyl)thio))metalphthalocyanine,
2(3),9(10),16(17),23(24)tetra((2E)-3-(4-phenyl)acrylicacid)metalphthalocyanine
and
2(3),9(10),16(17),23(24)-tetra(butyl(2E)-3-(4phenil)acrylate)metalphthalocyanine. Each complex has been doped into P3HT and F8T2 which are used as active
layer for OFET’s. After the fabrication of OFET’s, electrical characterizations have been carried out. According to the
measurements, especially p-coumaric butyl esther ZnPc doped devices represents the higest mobility values.
Dielectric layers and the dielectric/organic semiconductor interfaces have been investigated systematically by XRD
and AFM, and the mobility results have been compared As a result all dopant materials have improved the OFET’s
performances except p-coumaric acid substituted CoPc.
82
Can UÇKUN, Derek BAKER
Middle East Technical University (METU), TURKEY
Modeling and Simulations of Direct Steam Generation Solar Thermal Power Plant
In this paper a mathematical model of a parabolic trough solar collector array is presented. Unlike the conventional
parabolic trough collectors of today's commercially available solar thermal power plants, water is the heat transfer
fluid instead of synthetic oil. Using water instead of synthetic oil increases the efficiency of a solar thermal power
plant. Using water as heat transfer fluid does not require any heat exchangers to generate superheated steam.
Simulations are done using water through the absorber of parabolic trough collectors to generate superheated
steam to be used for a steam turbine to generate electricity. Steady state simulation results of a parabolic trough
solar collector array are compared with the published results of INDITEP project and good agreement are found.
With the help of the steady state results that are benchmarked against published data, a complete power plant
simulation is done using mathematical model of a parabolic trough solar collector array and compared with the
published results of the INDITEP project. The simulation study compared with the INDITEP project is then applied to
different locations of Turkey using TMY2 (Typical Meteorological Year 2) weather data files. The results are
analyzed and discussed for availability of solar thermal power plants using direct steam generation with parabolic
trough collectors in Turkey.
Aliekber AKTAĞ, Ercan YILMAZ, Raşit TURAN
Abant Izzet Baysal University, TURKEY
Structural and Adjustable Optical Band Gap Properties of Cd1-xZnxTe Thin Films
200 nm thick Cd1-xZnxTe thin films were deposited on glass substrates by using a single sputtering target.
Substrates were heated at 400 °C during the deposition process and deposited films were annealed at 300 °C and
450 °C for an hour under flowing N2 gas at atmospheric pressure. The in situ heating and post-deposition annealing
treatments on the structural and optical evolution of Cd1-xZnxTe films were studied by several diagnostic
techniques: X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM),
atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and UV-transmission spectroscopy. The
transmission spectra for both as-deposited and heat-treated CdZnTe samples were measured in the region of the
optical absorption band edge. Band gap measurements found to be in the range of 1.59-1.66 eV for deposited
films. The XRD studies revealed that the heated Cd1-xZnxTe films posses a cubic oriented (111), (220) and (311)
polycrystalline structure whereas unheated films are mostly amorphous. The effects of annealing temperature on
the composition of the films were determined and discussed. To understand the change in the chemical
composition of the films, XPS measurements were performed in the depth profiling mode. Results were compared
with the structural analysis obtained from the XRD measurements. Depending on preparation conditions and heat
treatments, desired optical band gap for various films may be adjusted and obtained. Results show that the Cd1xZnxTe thin film sputtered at 400 °C and annealed at 450 °C under N2 gas flow environment is one of the desired
film for its applications in photovoltaics and imaging devices. A further work is on the way to improve the
performance of these films.
83
Ayten CANTAŞ, Şebnem YAZICI, Mehmet Ali OLGAR, Metin KURT, Gülnur AYGÜN, Enver TARHAN, Lütfi
ÖZYÜZER
The Izmir Institute of Technology, TURKEY
XPS and RAMAN Studies of Cu2ZnSnS4 Thin Film Absorber Layer for Solar Cells
For thin film solar cell applications, having the direct energy band gap of 1.4-1.5 eV, a large optical absorption
coefficient above 104 cm-1 and p-type conductivity, quaternary compound of Cu2ZnSnS4 (CZTS) is one of the most
promising candidates among the possible photo-absorbing materials [1]. Also it is well known that CZTS is one of
the appropriate photovoltaic materials not only being low-cost solar cell but also consisting of earth-abundant
elements [2]. In this study, CZTS films were growth on Ti and Mo backcontact coated SLG substrate by dc
magnetron sputtering technique. Sn/Zn/Cu layers were sputtered and these deposited stacks were transformed
into CZTS films by sulfurization. The transformed CZTS films were characterized by X-ray Photoelectron
Spectroscopy (Specs) and Confocal Raman scattering (Scientific Instruments) measurements. The focus of this study
is being on secondary phases, CZTS surface composition and native oxidation for future development of solar cell.
XPS survey spectrum of CZTS verified the existence of Cu, Zn, Sn, S, and C. The detailed scanning Cu 2p, Zn 2p, Sn
3d, S 2p were also obtained. The Raman analysis includes possible CZTS peaks at 338 cm-1, 287 cm-1 and 252 cm-1
[3]. In addition, it is evident that there is additional peak related to the presence of other compound of SnS 190 cm1. In summary, we have shown that our CZTS films prepared with dc magnetron sputtering technique presented
majority CZTS phase and some secondary phases. The optimization of film stoichiometry and sulfurization process
are in progress. This study was partially supported by TUBITAK project 112T068. References 1) M. Danilson, M.
Altosaar, M. Kauk, A. Katerski, J. Krustok, J. Raudoja. XPS study of CZTSSe monograin powders, Thin Solid Films, 519,
2011, 7407–7411. 2) M. Bar, B.-A. Schubert, B. Marsen, R.G. Wilks, M. Blum, S. Krauseand, S. Pookpanratana, Y.
Zhang, T. Unold, W. Yang, L. Weinhardt, C. Heske, H.-W. Schock. Cu2ZnSnS4 thin-film solar cell absorbers
illuminated by soft x-rays, Journal of Materials Research Society, 27, 8, 2012, 1097-1104. 3) Hyesun. Yoo, JunHo.
Kim. Comparative study of Cu2ZnSnS4 film growth, Solar Energy Materials & Solar Cells 95, 2011, 239–244.
Duygu AKIN, Çağdas KOÇAK, Görkem OYLUMLUOĞLU
Mugla Sıtkı Kocman University, TURKEY
Effect of magnetic field on germanium pn junctions
In this study, effect of magnetic field which is perpendicular to junction current, on diffussion current has been
investigated in pn junction diodes, theoritically. The magnetic field dependent diffussion current experission has
been derived analitically. Resulting magnetic field dependent diode equation has been used to produced current –
voltage theoritical data for Germanium pn junction diodes. Using this data, current – voltage graphs, I(B) - V have
been plotted under different magnetic fields and effect of magnetic field on current – voltage characteristics has
been investigated. In these graphs, increasing magnetic field increases potential barrier Vbi decreases junction
current and reverse saturation current I0 have been observed. Also effect of magnetic field on static and dynamic
magnetoresistances, using Rd(B) – V ve Rs(B) – V graphs which is plotted using theoritical data, have been
investigated and increasing magnetic field increases static and dynamic magnetoresistance has been observed in
Germanium pn junctions.
84
Metin KURT, Şebnem YAZICI, Ayten CANTAŞ, Hasan KÖSEOĞLU, Lütfi ÖZYÜZER, Gülnur AYGÜN
The Izmir Institute of Technology, TURKEY
Bilayer Mo, W and Ti Film Deposited by DC Magnetron Sputtering as Back Contact for Thin Film
Photovoltaics
Due to the increasing shortage of natural source and costs of materials and electricity, it is inevitable transition to
renewable energy to satisfy the global energy demand. Nowadays, the photovoltaic cell is the most popular and
promising segment of renewable energy. Thin film solar cells such as CuInSe2 (CIS), Cu(In,Ga)Se2 (CIGS) and CdTe
are commercially available and will dominate the market soon. Molybdenum back contact is preferred for these
solar cells. Cu2ZnSnS4 (CZTS) thin film solar cells are novel and has potential because of earth abundant material
usage. There are many candidate materials, such as W, Mo, Cr, Ta, Nb, V, Ti, Mn have been examined for optimum
back contact material for CIS, CIGS and CdTe. Molybdenum is the most commonly used one since it has lower
resistivity, relative stability during the growth of thin film solar cell at the high temperature and it supplies the
graceful adhesion between the soda lime glass and the absorber layer [1]. On the other hand, it is not clear which
material is suitable for CZTS as a back contact. In this study, we optimized the deposition parameters of the bilayer
Mo, W and Ti back contacts with dc magnetron sputtering [2]. We covered bilayer Mo thin film as a back contact
owing to the fact that the bottom layer was formed at the higher working pressure to achieve a better adhesion
and the top layer was deposited at the lower working pressure to get a lower resistivity [1]. After the deposition
process, we measured the structural and electrical properties of back contacts. The resistivity, sheet resistance,
thickness and adhesion tests were done. The optimal properties for good back contact to CZTS will be discussed in
details. *This research is partially supported by TUBİTAK project with number 112T068. References [1] S. J. Kwon et
al. Applied Surface Science 257 (2011) 9682. [2] O. Tuna et al. J. Phys. D: Appl. Phys. 43 (2010) 055402.
Bengül METİN, Neşe KAVAŞOGLU, A. Sertap KAVAŞOGLU
Mugla Sıtkı Kocman University, TURKEY
Simulation model for lateral inhomogeneity of Au/n-GaN solar cell
Simulation softwares are powerful tools for exploration of solar cell behavior . 1D simulation is insufficient when
studying other effects like discrete shunts, weak diode areas, lateral inhomogeneities, contact geometries and grain
boundaries. On the other hand, electronic properties of Au/n-GaN solar cell depend sensitively on lateral
inhomogeneities. We present a new two dimensional (2D) simulation model for the mimic current-voltage behavior
of laterally inhomogeneous Au/n-GaN solar cell. Zero barier height inhomogeneity (Φbo), lateral fluctuations of
characteristic tunneling energy (Eoo) and shunt resistance inhomogeneity (Rsh) are important parameters for 2D
modelling. In this study, we will examine the effects on the current-voltage curves of these parameters for Au/nGaN solar cell.
85
Şebnem YAZICI
The Izmir Institute of Technology, TURKEY
Raman Spectroscopy, XRD and XRF Studies of Squentally Sputtered CZTS Absorber Layers in PV
Technologies
Raman Spectroscopy, XRD and XRF Studies of Squentally Sputtered CZTS Absorber Layers in PV Technologies S.
Yazici1,* M. A. Olgar2, A. Cantas1, M. Kurt1, G. Aygun1, E. Tarhan1, L. Ozyuzer1 1 Physics Department, Izmir
Institute of Technology Urla-Izmir 35430 Turkey 2 Physics Department, Karadeniz Technical University
*[email protected] In photovoltaic (PV) technologies, copper zinc tin sulfide abbreviated to CZTS is a
relatively new quaternary p-type semiconducting compound that considered to be substitute for other
chalcogenide-based solar cells Cu(In, Ga)(S, Se)2 (CIGS), (CIS) and CdTe. Despite the higher conversion efficiencies
of these compounds, restrictions on heavy metal usage for Cd and limited source and high cost of In and Ga,
restrict the production capacity of existing chalcogenide-based technologies. CZTS consists of earth-abundant, low
cost and environmentally friendly elements. CZTS has similar electrical and optical features and alike crystal
structure with CIGS which makes it promising candidate for PV systems. There are several vacuum-based or
nonvacuum deposition methods for CZTS thin films in literature [1, 2]. In the first part of our study, we deposited
Sn, Zn, Cu layers by sequential sputtering in two different stacking orders as Sn/Zn/Cu/Mo/glass and
Cu/Sn/Zn/Mo/glass. The absorber layer deposited on Mo-coated substrate to get electrical contact. The
sulfurisation reaction, formation of CZTS and second phases are studied by XRD, XRF and Raman spectroscopy as a
function of temperature and compositional modification of layers. Since S is introduced by reaction with the
precursor, the amount that is incorporated depends on the amount of the metal elements [3]. XRF analysis was
done to obtain composition ratios of Cu:Sn:Zn in CZTS. X-ray diffraction indicates a phase with confidence, but the
presence of coexisting second phases with similar symmetry and lattice parameters with pure CZTS. Means, it is
impossible to examine structure via XRD characterization solely. A way to distinguish CZTS from some of the
possible secondary phases is the Raman spectroscopy. Secondary phases should be avoided, especially those with
smaller band gaps (conductive phases) than the absorber layer, which cause reduction in the open circuit voltage of
the device and create shorting pathways through the absorber layer. Therefore it is better to obtain optimum
parameters for absorber layer primarily, and then design the rest of the device. In the light of the XRD, XRF and
Raman spectroscopy analysis we may put forward an idea to obtain preferable kesterite CZTS structure. *This work
is partially supported by TUBITAK (Scientific and Research Council of Turkey) project number 112T068 References
[1] H. Katagiri, K. Jimbo, W. S. Maw, K. Oishi, M. Yamazaki, H. Araki, A. Takeuchi, Thin Solid Films 517 (2009) 2455–
2460 [2] G. Zoppi, I. Forbes, R.W. Miles, P.J. Dale, J.J. Scragg, L.M. Peter, Pr
86
Eray TİMUR, Eray UZGÖREN, Musbaudeen BAMGBOPA
Middle East Technical University, Northern Cyprus Campus, Kalkanlı, TURKEY
Annual Performance Analysis of Dry and Wet Cooling Systems for a Small-scale CSP System in
Northern Cyprus
Rankine cycle is by far the most widespread way of power production in the world. Either lowering cold fluid
temperature or increasing hot fluid temperature can result in higher cycle efficiency. From this perspective, in a
Rankine cycle, cold side can be considered as much important, if not more, as the hot side. Cooling of the working
fluid is performed by means of a cooling unit on the cold side. Currently, most of the power plants around the
world utilize water cooling, i.e. once-through cooling and wet cooling. In once-through cooling, extra heat is
discharged directly into a large body of water such as lakes, rivers etc. However, this method is prone to strict
regulatory limitations due to high environmental footprint. In wet cooling, on the other hand, heat is discharged to
air by the water circulating in an open cycle. This method has been quite widespread since water has been
considered as cheap and abundant. However, considering their main mode of heat dissipation is by mass transfer,
wet cooling towers consume huge amount of water by evaporation which rises up environmental concerns in arid
regions. One obvious case is the places with high solar energy potential, where traditional method of wet cooling
can be infeasible as the regions with good solar potential usually have limited water resources. In this perspective,
consideration of alternatives is a study worth to conduct. Dry cooling systems constitute the main alternatives to
water cooling systems. Such systems are labeled as ‘dry’, because there is no need for make-up water. Actually,
one can save up to 90-95% of the water with dry systems. Nevertheless, the tradeoff for using dry cooling is mainly
the sacrifice of cooling efficiency especially on hot days which is quite likely in arid regions. The present study
focuses on the comparison of both configurations for conditions at Northern Cyprus. The system under
consideration is an ORC system run by small-sized parabolic through collectors while cooling is achieved by means
of a wet-cooling tower already in place. The main focus of the research is to observe the differences between two
technologies in terms of their influences on the whole system and to see if dry cooling is promising for solar
thermal systems; moreover, to see if there is any room for improvement.
Çağdaş KOÇAK, Duygu AKIN, Görkem OYLUMLUOĞLU
Mugla Sıtkı Kocman University, TURKEY
A magnetoresistance investigation on AlGaInP/GaInP quantum well structure at room temperature in
dark
In this work, the dark current voltage properties of a pn homojunction and AlGaInP/GaInP quantum well structure
have been investigated under dc magnetic field at room temperature. Measurements have been carried out at
different angles, that is the angle between magnetic field and junction current. Changing the angle and magnetic
field from 0 T to 1 T with 0.1 T step, the measurements were taken at room temperature and angle dependence
were not found. Besides the magnetis field dependence of the electronic properties such as current – voltage,
percent change of junction current, magnetoresistance and percent change of magnetoresistance MR %, have been
investigated. The percent change of magnetoresistance (MR %) shows a huge change as ~10^5 near side of zero
bias. Either positive or negative MR % were also found. The observed change in current voltage characteristics
under magnetic field is due to the modifications of energy band profile of investigated structure caused by
quantum mechanical interactions such as spin – magnetic field interaction, the magnetic field dependent singlet
and triplet spin state ratio.
87
Mehrdad Fouj LALİ, Reza JALİLİ
Urmia University, IRAN
Maximum Power Point Tracking(MPPT) With Fuzzy Controller For Reducing Power Loss in Maximal
Power Point of Photovoltaic Systems
Numerous maximum power point tracking techniques have been proposed for maximizing output power of
photovoltaic arrays, which continuously track the maximum performance point of system. Variations of this point
are also proportional to changes in radiation (light) intensity and temperature. Although many tracking techniques
have been offered in the literature but perturbation and observation method has been mostly favored thanks to its
simplicity and low cost of implementing maximum power point tracking algorithm. One problem of this algorithm is
the fact that performance point fluctuates around the maximum power point in the steady state leading to loss of a
percentage of the available power. Additionally, perturbation and observation algorithm is slow and not capable of
accurately tracking maximum power point in the event of abrupt and rapid atmospheric changes. Selection of
variations with fixed and uniform size will contribute to reaching an optimally agreed solution between the
transient and steady states; however, this response is not the best. A control method based on fuzzy control is
introduced in the current paper, which primarily will produce better response because of using non-fixed changes.
In other words, it will yield faster response in transient state and less fluctuations around the maximum power
point in the steady state. Also, the slowness pitfall is alleviated due to the modifications imposed to this algorithm.
Zafer ARTVİN, Tuba OKUTUCU-ÖZYURT, M. Pınar MENGÜÇ
Middle East Technical University (METU), TURKEY
Fabrication Of Nanostructured Samples For The Investigation Of Near Field Radiation Transfer
Radiative heat transfer in nanostructures with sub-wavelength dimensions can exceed that predicted by Planck's
blackbody distribution. This increased effect is due to the tunneling of infrared radiation between nanogaps, and
can allow the eventual development of nano-thermo-photo-voltaic (Nano-TPV) cells for energy generation from
low temperature heat sources. Although near field radiation effects have been discussed for many years,
experimental verification of these effects is very limited so far. In this study, silica coated silicon wafer sample chips
have been manufactured by using MEMS fabrication methods for testing the near field radiation effects. A variety
of samples with 1×1, 2×2 and 5×5 mm^2 area, and with 25 nm, 50 nm, 100 nm and 200 nm (nano-gap) separations
have been prepared. 3D structures with vacuum gaps have been obtained by bonding of the silica coated wafers.
The samples have been tested in an experimental setup by a collaborative group at Özyegin University, İstanbul. An
increase in the net radiation heat transfer with decreasing nano-gap size has been reported by the Özyegin group
who used these samples in a parallel study. The present work outlines the micro-fabrication techniques used for
the sample preparation. Also, the problems we have faced during the fabrication process are discussed.
88
Adem YENİSOY, Turgut TUT, Osman KODOLBAŞ, Sebahattin TÜZEMEN
TUBITAK, TURKEY
Improvement of photovoltaic conversion efficiency of dye-sensitized solar cells using Au plasmonics
Self assembled Au nanoparticles having localized surface plasmon resonance (LSPR) property were embedded into
different layers of dye-sensitized solar cells (DSSCs). Depending on the plasmonic layer position, two-face of
plasmonics (field enhancer and scattering center) were investigated. When plasmonics were presented in TiO2
matrix, short range existence of enhanced internal field due to Au plasmonics was shown and photovoltaic
conversion efficiency was raised by 20% in DSSCs. Integration of self assembled Au plasmonics in TiO2 matrix
presents strong absorption of incoming photons which results in improvements on device parameters. While their
integration on top of cell, plasmonics improves scattering from top surface leading to a decrease on photovoltaic
conversion efficiency of DSSCs due to prolonged optical paths depending on TCO/glass thickness.
Gökçe YILDIRIM, S. Behlül KURAN, İ. Yoldaş KARABULUT, Mustafa ATİLLA, Veysi İŞLER, Ahmet Oğuz
AKYÜZ
Simsoft Computer Technologies Ltd., TURKEY
A Decision Support System Based On Solar Energy Simulation and Optimization
Accurate estimation of solar power at a given date, time, and location, as well as the electrical energy that will be
accumulated by a solar power plant at that location and within a given period are important problems due to high
investment costs of solar power plants. Therefore, a decision support system can provide immense benefits in this
regard. In this paper, we present such a decision support system that allows: (1) calculation of solar power at any
location by taking into account the topographical features of the region, (2) calculation of electrical energy by a
hypothetical solar power plant with features specified by the user, (3) optimization of the power plant such that
the maximum possible energy is collected at a given location and within a specified duration. Our system is capable
of incorporating the effects of terrain shadowing as well as self-shadowing that occurs between the solar panels.
We also discuss the accuracy of our results by comparing our findings with the real measured data. The details of
this system and solutions to various challenges encountered during the development are elaborated in this paper.
Deneb MENDA, Orhan ÖZDEMİR, Osman KODOLBAŞ, Okan YILMAZ, Özlem PEHLİVAN, Kubilay KUTLU
Yildiz Technical University, TURKEY
Effects of Substrate Temperature and Annealing on PECVD Grown HIT Solar Cells
A modified admittance analysis was applied on PECVD grown HIT solar cells ((n)a-Si:H/(i)a-Si:H/(p)c-Si). Moreover,
effect of substrate temperature during growth and annealing effect on both solar cell parameters and admittance
analysis were also carried out in this work.
89
Pelin KAVAK, Elif Altürk PARLAK, Nesrin TÖRE, Orhan ÖZDEMİR, Kubilay KUTLU
Yıldız Technical Universty, TURKEY
Observatıon Of Negative Capacitance In Ito/ Pedot:Pss/Pcdtbt:Pcbm/Tiox /Ca:Ag Organic Solar Cells
Negative capacitance was observed in ITO/PEDOT:PSS/PCDTBT:PCBM/TiOx/Ca/Ag organic solar cells. PCDTBT, one
of the next generation materials being developed for organic photovoltaics (OPV) was investigated by means of
structural and electrical features. UV-Visible measurements indicated energy bandgap of 1,8 eV determined via
absorption that onset at 660 nm and the absorption bands (at 401 and 577 nm) that was the one of the factor
affecting the efficiency of organic solar cells. Another factor to achieve high power conversion efficiency (PCE)
(more than 6%) of PCDTBT over P3HT was its deeper HOMO energies that increased Voc (0.9 V rather 0,6 V).
Thermal behavior was characterized by thermo gravimetric and differential thermal analysis (TG/DTA) analysis,
showing that a glass transition at 120 0C and excellent thermal stability at 400 0C. Fabricated bulk heterojunction
solar cells (in the form of ITO/PEDOT:PSS/PCDTBT:PCBM/TiOx/Ca/Ag structure) yielded Voc of 0,86 V, a Jsc of 4,8
mA/cm2 and a fill factor of 0,43 under simulated AM 1.5 G (100 mW/cm2 ) conditions resulting PCE of %1.5 in
current-voltage measurements. In dark I-V curve, two conduction mechanisms (ohmic and space charge limited
current) were identified. Under bias conditions of space charge limited conduction mechanism, negative
capacitance was observed from admittance measurements, Y(=G+jwC with G=conductance, C=capacitance and w=
angular frequency). Investigations are still on the way to find out the reason for negative capacitance (inductance)
effect.
Mustafa CAN
Ege University Solar Energy Institute., TURKEY
Synthesis And Photovoltaic Applications Of Two Novel Dyes Based On Triarylamin
Dye-sensitized nanocrystalline TiO2 solar cells (DSSCs) ,which possess high conversion of sunlight to electricity, by
means of harvesting of solar irradiation by the sensitizer, have attracted considerable attention in scientific
research and practical applications [1,2]. Originally, ruthenium polypyridine complexes were the dominating
sensitizers used in this area [2] but since 2000 many classes of organic dyes were systematically investigated and
some of them achieved impressive photo-conversion efficiencies around 10% and even higher [3–5]. Two novel
dyes based on triarylamines as sensitizer have been synthesized. After that, The EHOMO and the ELUMO levels of
these novel dyes have been calculated by using cyclic voltammetry. The dye sensitized solar cell applications have
been carried out. The device structure is FTO/nc-TiO2/Dye/I-/I3-/Pt/FTO. Dye sensitized solar cells have been
characterized by current-voltage (I-V) measurement. All current-voltage (I-V) measurements have been carried out
under 100 mW/cm2 light intensity and AM 1.5 conditions.
90
Halil ARSLAN, A. Tasdemir, Gülnur AYGÜN, Lütfi ÖZYÜZER, U. ÜNAL
The Izmir Institute of Technology, TURKEY
Solar Control with Electrochromic Glasses
Solar Control with Electrochromic Glasses H. Arslan*,a, A. Tasdemira, G. Ayguna, U. Unalb, L. Ozyuzera
aDepartment of Physics, Izmir Institute of Technology, Urla, 35430, Izmir, Turkey bDepartment of Chemistry, Koc
Univeristy, Sarıyer, 34450, Istanbul, Turkey *Corresponding author E-mail: [email protected] Electrochromic
(EC) materials and devices have many applications such as in vehicles and buildings, because it can control sun
light, save energy in terms of heating and cooling, and also protect from harmless light. Electrochromic windows
consist of 5 layers [1]. In this study, we prepared all layers of EC device and fabricated the window. First of all, two
glasses were coated Transparent Conductive Oxide (TCO) Indium Tin Oxide (ITO) by magnetron sputtering
technique [2] and their surface resistivities were measured. One of ITO coated glass was deposited electrochromic
film Tungsten Oxide (WO3) and the other was deposited ion storage film Prussian Blue (PB) by electrochemical
method. The thickness and optical transmittance of both WO3 and PB were measured. Polyvinlybutral (PVB) was
investigated as ionic conductive polymer electrolyte. PVB was used because of its unique properties such as high,
adjustable adhesion to glass, high optical transparency, excellent toughness and flexibility, high impact strength
and temperature resistance [3]. LiClO4 was added to PVB for improvement of ionic conductivity. The temperature
dependence of ionic conductivity is measured for various addition of LiClO4 to PVB using impedance analyzer. Then
these two multilayered glasses were laminated with PVB, and EC window was obtained. The final window has
Glass/ITO/PB/PVB/WO3/ITO/Glass structure. The light transmittance of smart glass is measured. The coloring and
bleaching time are also measured. Keywords: Electrochromic, Thin film Growth, Smart glasses, Ionic conductors,
Polymer electrolyte, Transparent Conducting Oxide References : [1] C. G. Granqvist et al., Appl. Phys. A 89, 29–35
(2007) [2] O. Tuna et al., J. Phys. D: Appl. Phys. 43, 055402 (2010) [3] H. Stenzel et al., Glass processing days 2003,
Conference Proceedings Book, pp. 423–426.
Metin AKTUĞ, Süleyman ÖZÇELİK
Gazi University, TURKEY
Island Mode Dc / Ac Inverter Based On A Study On The Development Of Two Axis Sun Tracking System
Around the world, increasing electical energy demand amplified the interest and improved the utilization of
distributed renewable energy generation systems. Continuously increasing electrical energy consumption overloads
both electrical distribution systems and power stations which has serious consequences on power availability,
security and quality. Consequently, solutions are needed which are technically feasible and match the conditions of
sustainability. Solar City Planning and Construction was emphasized by our research. During our research, a system
run by one solar cell is implemented and experements are done in various conditions. Effect of light obtained,
short-circuit current, open-circuit voltage, filling factor, effect of temperature on the panel, ideal battery charge
data, the ideal battery charge data were evaluated with a master card mikroişlenci controlled. Microprocessorcontrolled synchronous network as a result of the findings, and the island mode is an ideal type of solar cell system
suitable for use in the application circuit is designed with two axis sun traking system which the context of
maximum power and maximum efficiency. This electronic circuit is recommended that our design is efficient. This
electronic circuit is recommended that our design is in terms of solar energy efficiency.
91
Sertap KAVASOĞLU, Nese KAVASOĞLU
Mugla Sıtkı Kocman University, TURKEY
Simulation for electrical properties of Graphene/SiO2/GaN device structure
GaN based devices are highly promising optoelectronic devices for many years due to their useful applications in
photovoltaic energy conversation, fiber optic communication and atmosphere monitoring. GaN based devices such
as Schottky barrier, and p-i-n structure have been fabricated and characterized so far. A proper understanding of
the admittance spectroscopy result is crucial since it is a powerful tool to calculate the physical and electronic
parameters of a device. In this study, temperature dependent dark current–voltage (I–V) and dark admittance
spectra of Graphene/SiO2/GaN (MIS) device structure have been studied with current–voltage and admittance
spectra by simulation. The temperature dependent forward bias current-voltage characteristics of Graphene/
SiO2/GaN device are considered to behave like the Schottky junctions where carrier injection is especially
influenced by the carrier generation, recombination and tunneling in the junction interface. All current–voltage
characteristics exhibited good rectification behavior. The forward and reverse bias capacitance–voltage (C–;V)
characteristics of the Graphene/SiO2/GaN device were simulated at different probing frequency. All capacitance
spectra exhibited dispersion relation. Frequency depended dielectric loss tangent spectra of Graphene/SiO2/GaN
device at different DC bias voltages also show significant peak.
Burak SEFER, Pınar MENGÜÇ, Onur YAZGAN
Ozyegin University, TURKEY
PV System Performans Analysis by Comparing the Developing PV System Software Values and Real
Data from Mounted PV System
In this presentation, we will discuss a new software developed to assess different engineering and economic
aspects of photovoltaic systems which can be built at different locations in Turkey. The software is based on
theoretical and actual calculations for different PV systems and allows side-by-side comparisons of different
scenarios at a given location. The weather and solar data are integrated into the software along with the actual
specifications of different modules, inverters, cabling, construction, electrical and mechanical components, and
installion alternatives. A detailed economic analysis is part of the software to allow the user to compare different
investment and return-on-investment figures. This software is currently employed to compare different panels’
performances to be installed at Ozyegin University/CEEE Roof. This study will allow engineering and economic
decisions of solar PV installations with more precision and with real time data control.
92
Metin AKTUĞ, Süleyman ÖZÇELİK, TOFIG MEMMEDL
Gazi University, TURKEY
Ada Modlu Dc/Ac Evirici Temelli İki Eksenli Güneş Takip Sisteminin Geliştirilmesi
Around the world, increasing electical energy demand amplified the interest and improved the utilization of
distributed renewable energy generation systems. Continuously increasing electrical energy consumption overloads
both electrical distribution systems and power stations which has serious consequences on power availability,
security and quality. Consequently, solutions are needed which are technically feasible and match the conditions of
sustainability. Solar City Planning and Construction was emphasized by our research. During our research, a system
run by one solar cell is implemented and experements are done in various conditions. Effect of light obtained,
short-circuit current, open-circuit voltage, filling factor, effect of temperature on the panel, ideal battery charge
data, the ideal battery charge data were evaluated with a master card mikroişlenci controlled. Microprocessorcontrolled synchronous network as a result of the findings, and the island mode is an ideal type of solar cell system
suitable for use in the application circuit is designed with two axis sun traking system which the context of
maximum power and maximum efficiency. This electronic circuit is recommended that our design is in terms of
solar energy efficiency.
Mimoun ZAZOUI, Y. MİR, A. AMİNE, K. ZAZİ
University of Hassan II Mohammedia – Casablanca, MOROCCO
The window layers effect on the hardness improvement of space solar cells exposed to the 1 MeV
electron irradiations
Because of their state of art technology, GaAs solar cells are generally preferred for spatial applications. Exposure
to Proton and electron irradiations, solar cells suffer significant degradation in their performance such as short
circuit current and open circuit voltage. Adding a window layer helps in effectively reducing the surface
recombination at the emitter surface of the solar cell without absorbing the useful light required for the device. It
remains to study the physics of the window-emitter hetero-interface, in order to understand how the window layer
presence increases the minority carrier lifetime of the solar cell exposed to particles irradiation. In this work
Numerical simulation was used to study the AlxGa1-xAs window composition effect on the current–voltage
characteristics of a GaAs solar cell under AM0 illumination and exposed to 1 MeV electron irradiation. To predict
the effect of window layers on solar cells degradation, the current voltage characteristic are evaluated for different
electron irradiation fluences. The study results are supported by experimental data. The results show how the
window layer improves resistance to electron irradiation through its own parameters.
93
Gülin Acarol ZİLANLI, Bedrettin UZUN, Ömer AKAN, Aynur ERAY
Hacettepe University, TURKEY
Outdoor Performance Evaluation of a-Si Modules in Beytepe- Ankara Climate Conditions
Outdoor Performance Evaluation of a-Si Modules in Beytepe- Ankara Climate Conditions Gülin Acarol Zilanlı1,
Bedrettin Uzun1, Ömer Akan1. Aynur ERAY1, 2 1Hacettepe University, New and Clean Energy Research-Application
Center, Beytepe, Ankara 2Hacettepe University, Department of Physics Eng., 06800 Beytepe, Ankara This paper
aims the performance evaluation of a series of a-Si PV modules, mounted three different times in Beytepe- Ankara
climate conditions. The Hacettepe Beytepe Solar House was designed and built in 2000 to meet it’s electricity
demand from solar energy. This was achieved by using a-Si Dunasolar (type DS40) PV modules placed on the façade
of the solar house. The PV modules were faced south with a tilt to horizontal 40◦. At the beginning, 23 a-Si
Dunasolar (type DS40) PV modules were mounted, and then additional 15 a-Si Dunasolar (type DS40) PV modules
were placed to increase the capacity of the system, in 2006. All PV modules were identical and bought at the same
time. Performance of a PV module depends on solar irradiation, module temperature and air mass, whereas
comercially available PV modules are given power ratings at standart test conditions (STC - G=1000 W/m2, T=25°C,
AM1.5 spectrum). The PV modules never meet their performances specified under the STC condition when they are
operated at outdoor conditions. Different PV technologies are prone to behave differently under seasonal
variations because of distinct spectral responses, and different temperature coefficients of current and voltage.
When the values of temperature and irradiance differ from STC, the output power also differs. For this reason,
depending on the installation they can face the following climatic stress factors: such as solar irradiation,
temperature, humidity, wind, snow and dust. In order to compare PV module performance with each other, it is
necessary to translate the measured data to STC. Therefore, experimentally measured values of current and
voltage at outdoor conditions, were translated to STC following IEC Standarts. The PV modules are disconnected
from the system during the measurements of their I-V characteristics. Since the relative performance of a-Si
modules is highest at low air mass coditions, represents noon time, all measurements are taken at noon. During the
experiments, solar radiation was measured by Kipp & Zonnen CM 11 pyranometer. It is observed that some a-Si
modules have visual degradation which causes additional power losses. For 12 years old modules, it has been
observed approximately 25%, 19% and 10% power decreases in visually-degraded and visually-clean module
mounted at 2000, visually-clean module mounted at 2006 respectively, while the increase in 12 years old but
unused one was approximately 18%, in accordance with the literature.
94
Hoda HAFEZ, H. SHİBL, M. SAİF, M. S. A. Abdel MOTTALEB
Environmental Studies and Research Institute, Minoufiya University, EGYPT
Er3+-doped titania/nanoporous titania bi-layered electrodes for DSSCs applications; Up-conversion
achievement
Currently, one of the major limits for the efficiency improvement of the dye-sensitized solar cells is ascribed to the
partial spectral matching between the incident solar photon spectrum and the absorption spectrum of the dye
sensitizers which is mainly in the visible region (up to 800nm). However, 50% of solar irradiation is in the ultraviolet
and infrared regions, and thus is not utilized. This limits the solar energy conversion efficiency for DSSCs. Therefore,
a novel approach in this study is to extend the spectral response range of the DSSC by spectral modification
through the phenomenon of up-conversion (UP) of low energy photons into the visible region. Rare earth elements
are especially suitable for optical up/down applications, since they have unfilled 4f and 5d shells. Er3+ -ion is
probably the most widely studied among the rare-earth ions that show up-conversion photoluminescence (UC-PL)
because it provides the long-lived intermediate level 4I11/2 easily accessible with a diode laser at 980 nm and has
rather high up-conversion efficiency. The evaluation of the photoluminescence (PL) properties and the mechanisms
of the energy transfer to Er3+ from the host semiconductors have been executed extensively. In addition to,
several papers have reported the up-conversion properties of Er3+ doped in TiO2 thin films. However, this is the
first time to apply Er3+ -doped TiO2 up-conversion thin layers in DSSCs. In the present work, nanostructure TiO2
thin films pure and doped with 0.01, 0.02 and 0.05 mole% Er3+ are prepared by simple sol-gel methods. The crystal
structure and morphology of the different Er3+-doped TiO2 thin films have been investigated by XRD, SEM, and UVVis diffuse reflectance. The visible emission properties of different prepared Er3+-doped TiO2 thin films have been
investigated by excitation with different wavelengths in the range of (700-800nm) where, the green and red
luminescence from intra-4f transitions of erbium ions in TiO2 are explained in details. It has been found that the
photoluminescence intensity increases with increasing Er3+-ion concentration. The detailed Er3+ up-conversion
mechanism are schematically discussed in details. Bi-layer DSSCs based on Er3+-doped TiO2 thin film electrodes
have been fabricated and showed a conversion efficiency (η) of 4.74%, 5.17 and 4.18%, for the 0.01, 0.02 and 0.05
mole% Er-doped electrodes, respectively, which is higher than that of the pure TiO2 film electrode (η = 4.17%). A
maximum efficiency enhancement (24%) has been achieved by applying 0.02 mole% Er3+-doping. This
enhancement in the overall efficiency achieved by applying the up-converting layer on the titania electrode has
been attributed to the up-conversion luminescence characteristics of Er3+ ions, which has been confirmed by its PL
measurements.
Mona SAİF, H. HAFEZ, M. S. A. ABDEL-MOTTALEB
Faculty of Education, Ain Shams University, EGYTP
Down-converting lanthanide doped TiO2 photoelectrodes for efficiency
Lanthanide (Ln3+) doped TiO2 down-conversion photoelectrodes (Ln3+ =Eu3+ and Sm3+ ions) are used to enhance
the photovoltaic efficiency of dye-sensitized solar cells (DSSC). We report on achieving fill factors of 0.67 and 0.69
and efficiencies of 5.81% and 5.16% for Sm3+ and Eu3+, respectively. This is compared to the 4.23% efficiency for
the undoped-titania photoelectrodes. This enhancement is probably due to the improved UV radiation harvesting
via a down-conversion luminescence process by the lanthanide ions. The structure, optical and photoluminescence
properties of the down-converting photoelectrode are characterized by X-ray diffraction (XRD), scanning electron
microscope (SEM), energy dispersive X-ray (EDX) and room temperature photoluminescence excitation and
emission spectrofluorimetric measurements.
95
Görkem OYLUMLUOĞLU, Çağdaş KOÇAK, Duygu AKİN, Neşe KAVASOĞLU, A. Sertap KAVASOĞLU
Mugla Sıtkı Kocman University, TURKEY
Magnetoresistance investigation of a Si pn homojunction at room temperature in dark
In this work, the dark current voltage properties of a Si pn homojunction have been investigated under dc magnetic
field at room temperature. Measurements have been carried out at different angles, that is the angle between
magnetic field and junction current. Changing the angle and magnetic field from 0 T to 1 T with 0.1 T step, the
measurements were taken at room temperature and angle dependence were not found. Besides the magnetic field
dependence of the electronic properties such as current – voltage, percent change of junction current,
magnetoresistance and percent change of magnetoresistance MR %, have been investigated. The percent change
of magnetoresistance (MR %) shows a huge change as ~105 near side of zero bias. Either positive or negative MR %
were also found. The observed change in current voltage characteristics under magnetic field is due to the
modifications of energy band profile of investigated structure caused by quantum mechanical interactions such as
spin – magnetic field interaction, the magnetic field dependent singlet and triplet spin state ratio.
Ferhat ASLAN
Harran University, TURKEY
Effect of S/In ratio on morphological, optical and structural properties of dip-coated CuInS2 thin films
CuInS2 thin films were prepared by sol-gel dip-coating method on glass substrates using 4, 6 and 8 molar ratios of
S/In in the solution. Cu/In ratio in the precursor solutions were fixed as 1.25. The prepared films were annealed at
420 oC and 460 oC for 30 min under argon environment. The effect of S/In ratio on the structural, optical and
morphological properties of CuInS2 films was investigated by X-ray diffraction (XRD), UV–Vis transmittance
spectroscopy and scanning electron microscopy with an energy dispersive X-ray spectrometer. XRD results showed
that the films exhibit polycrystalline tetragonal CuInS2 phase with (112) orientation. The remarkable effect of S/In
ratio on physical properties of the CuInS2 films was identified.
Makbule BİLGEN, Fırat ES, Mete GÜNÖVEN
Middle East Technical University Center for Solar Energy Research and Applications (GUNAM), TURKEY
Effect of Ag Nanoparticles Embedded in ZnO on the Performance of the n-type Solar Cells
In recent years, solar cells based on n-type crystalline silicon wafer have attracted great attention due to its
potential for high efficiency exceeding 20%. N-type Si have higher minority carrier diffusion length, higher tolerance
to common metallic impurities such as Fe . Moreover, they do not suffer from boron-oxygen defects which cause
light induced degradation in p-type substrate. However, fabrication of n-type solar cells has some process
difficulties such as B doping for p-type layer formation. These difficulties need to be eliminated for a large scale ntype solar cell production. On the other hand, solar cell efficiency can be improved by an effective light trapping
which is traditionally provided by surface texturing. Alternatively, Light trapping can also be provided using
plasmonic properties of metallic nanoparticles formed on or under the solar cell. In this work, we combine the ntype solar cells with the enhancement of metal nanoparticles formed on the back surface of the n-type solar cell.
For this purpose, back side of the cell is covered with ZnO in which metal nanoparticles are embedded. We study
the performance parameters of the n-type solar cells with the inclusion of metal nanoparticles.
96
Zeynep Deniz EYGİ, Ujjwal DAS
Canakkale Onsekiz Mart University, TURKEY
Effect of Hydrogen Dilution Ratio and Plasma DC on Passivation Quality of a-Si:H(i) Layer
In silicon heterojunction solar cells, suppression of a-Si:H/c-Si interface recombination is a key factor for gaining
high open circuit voltage. Inserting a thin intrinsic amorphous silicon (a-Si:H(i) ) film between doped layers and c-Si
reduces defect states and hence recombination at the a-Si:H/c-Si interface. Since a-Si:H(i) has low defect density
and high optical band gap, it is an ideal buffer layer for passivation of the crystalline silicon interface. The
passivation quality primarily depends on structural, optical and electronic behaviors of a-Si:H(i). The properties of
a-Si:H(i) are mainly affected by the growth conditions. In order to achieve a good passivation, the growth condition
of a-Si:H(i) must yield low defect density with avoiding damaging epitaxial growth on the surface of the c-Si. In this
work, a-Si:H(i) layers were investigated in terms of their passivation quality with varying hydrogen dilution ratio
(H2/SiH4) at two different growth power. a-Si:H(i) layers were growth on float zone p-type single crystalline Si by
Plasma Enhanced Chemical Vapor Deposition (PECVD).The surface passivation quality was evaluated by measuring
effective minority carrier lifetime (τeff) using QSSPC (quasi steady state photo conductance) measurement and Si-H
bonding configuration in a-Si:H(i) films was examined by FTIR spectroscopy. In this study the optimum growth
condition of a-Si:H(i) yields an effective lifetime of ~1 ms at an injection level of 1015 cm-3 with an implied Voc of
~700 mV.
Fırat ES, Mustafa KULAKCI, Raşit TURAN
Middle East Technical University Center for Solar Energy Research and Applications (GUNAM), TURKEY
A New Light Trapping Approach For Multicrystalline Solar Cells By Metal Assisted Etching
Light trapping ability of the solar cells is becoming a very important as the thickness of the cells are reduced for
more efficient charge collection and less material usage. Although alkaline texturing provides sufficient light
trapping for monocrystalline cells, it cannot be applied to multicrystalline cells due to crystallographic variations of
the etching process. In this study, we used metal assisted etching (MAE) as a texturing method for multicrystalline
solar cells. HNO3 was used as an oxidizer together with HF, AgNO3 to form random nano-structures on the surface
by MAE. The effect of parameters such as solution concentration and etching duration on reflection of the wafers
and SEM images of the surfaces are analyzed for material characterization. It has been observed that an increase in
the HF concentration and a decrease in the HNO3 concentration of the solution lead to structures close to
nanowires. The etching time had a positive effect on decreasing the reflection from the surface. Together with
etching time, an increase in one of the chemicals, AgNO3/HF/HNO3 also leads to a decrease in reflection. Surfaces
with nearly zero reflection throughout the visible spectrum have been demonstrated without any anti-reflective
coating on top.
97
Ildar SALAKHUTDİNOV, Murat ÖZTÜRK, Alpan BEK
Middle East Technical University (METU), TURKEY
Plasmonic frequency conversion devices for enhanced efficiency solar cells
In order to be competitive with other alternative energy sources like wind energy as well as comparing with
traditional carbon-based energy sources thin film solar cells should be more efficient than currently commercially
available. One of ways of improving efficiency of solar cells is using thin silicon films with additional layers and thin
films. Plasmonics is one of the most promising methods of improving solar cells efficiency. Plasmonic structures are
compact; they can work with very small amount of material yet providing dramatic improvement of light
conversion efficiency. One of problems of silicon-based solar cells is that, they are not able to absorb effectively in
the whole solar energy spectra. This is true regarding IR part of spectra and silicon is not an effective material for
wavelengths above 1100 nm. To solve this problem we are proposing to use plasmonic structures which can
convert light frequency in order to deliver additional solar energy into the part of optical spectra where silicon can
work more effectively. We are going to use two types of surface plasmon modes: long-range surface plasmonpolaritons (LRSPP) and localized surface plasmons (LSP). Each type of plasmon mode has its advantages and
disadvantages. LRSPP structures can be fabricated by using simple technology like thin film deposition and
evaporation but its frequency conversion efficiency on the flat surface is not very high. LSP can achieve very high
conversion efficiency but at this moment fabrication of these structures requires very sophisticated tools like ebeam lithography which can limit perspectives for potential mass production. In our work we are using advantages
of both approaches in the same time using new methods to eliminate their disadvantages. We created LRSPP
structures by periodic modulation of thin film layers used in this geometry. This approach allows increasing
frequency conversion efficiency up to one million times relative to a flat surface. Moreover, using periodic
structures we can control in- and out-coupling of light. Periodic structures were fabricated using conventional and
holographic optical lithography process. For LSP we are trying to maximize light energy conversion into optimal part
of spectra using plasmonic nanoantennas which include dipole-dipole structures, bow-tie geometry, and “hot spot”
interaction between two LSP. In addition we are using standard UV-lithography to fabricate LSP structures using
new principles of plasmonic lithography and nanoparticles self-organization. These methods can eliminate the
necessity of sophisticated and expensive technologies having in mind potential for mass production.
Engin ÖZKOL, Gizem NOGAY, Serkan KINCAL, Raşit TURAN
Middle East Technical University Center for Solar Energy Research and Applications (GUNAM), TURKEY
A Different a-Si Thin Film Sample Preparation Method for ESR Measurements
We propose a new sample preparation method for thin film amorphous silicon electron spin resonance (ESR)
spectroscopy. Up to now, films were deposited on a sacrificial substrate and then substrates were chemically
etched. The dried silicon flakes were collected in ESR quartz tubes and purged with He. In our case, we deposited
the a-Si thin films on the ESR quartz tubes and then immediately put the into untransparent boxes to avoid light
induced degradation. They were taken out only for measurements. In this paper, we used two different plasma
sources for deposition. The first one is the commonly used capacitavely coupled RF plasma (CCP) and the second
one is the inductively coupled RF plasma (ICP). The results showed that the ICP deposited films have higher defect
densities when compared to CCP deposited films.
98
Vildan BİLGİN, Kadir ERTÜRK, Barbaros DEMİRSELÇUK, Emrah SARICA
Canakkale Onsekiz Mart University, TURKEY
Studies on Fabrication and Characterization of n-CdS/p-Si Heterojunction Solar Cells
In this work, cadmium sulfide (CdS) films were grown by ultrasonic spray pyrolysis (USP) technique onto p-Si
substrates at the substrate temperature of 300C using aqueous solution of cadmium chloride and thiourea salts.
The electrical, optical properties and surface morphologies of the films were characterized by using I-V
characteristics, UV/VIS spectrophotometer and atomic force microscope, respectively. The variation in electrical
properties, surface morphologies and optical parameters such as transmittance, absorbance and energy band gap
of the films with the spraying duration (20, 30, 40 and 50 mins.) was investigated. Optical analyses indicated that all
films have almost high optical transmittances of ~60-70%. From the AFM images, it was seen that the surface
morphologies and the RMS roughness of the CdS films does not change significantly as a function of the spraying
duration except for the films whose spraying duration is 30 mins. Acknowledgement: This study was carried out
under project TBAG-111T057, “Structural, Optical and Electrical Properties of n-CdS:Al/p-Si heterojunction
prepared by the ultrasonic spray pyrolysis technique”, supported by TUBITAK (The Scientific and Technological
Research Council of Turkey).
Emine Hande ÇİFTPINAR, Fırat ES, Olgu DEMİRCİOĞLU, Raşit TURAN
Middle East Technical University Center for Solar Energy Research and Applications (GUNAM), TURKEY
A New Selective Emitter Technique Based On Single Step Doping For High Efficiency Crystalline Si Solar
Cell
Selective emitter is a well known approach for crystal silicon solar cell technology to reach improved cell
efficiencies over conventional methods. In a selective emitter cell design, dopant concentration beneath the
metallization contacts is higher (~50-60 Ohm/square) compared to the rest of the cell surface area (~80-100
Ohm/square). As a result, blue response is improved, emitter saturation current is reduced and contact resistance
is decreased. However, obtaining different doping concentrations over the cell makes production process more
complex and infeasible due to additional masking and a second doping step. In this work, single step doping
through laser grooved oxide mask has been studied. Oxide thickness, laser scribing and alkali cleaning steps have
been optimized to reach the sheet resistance values targeted for an efficient cell design. c-Si solar cells have been
fabricated using this new selective emitter approach. As a result, we have shown that solar cells based on this new
selective emitter structure can be used to fabricate higher conversion efficiency values compared to standard cell
design.
99
Özge Tüzün ÖZMEN, Mehmet KARAMAN, Rasit TURAN
Düzce University, TURKEY
Structural And Optical Analysis Of Polysilicon Films Formed By Solid Phase Crystallization At Different
Annealing Temperatures
Large-grained and low-cost thin-film polycrystalline silicon thin films can be fabricated on foreign substrates, such
as glass, quartz, ceramics, glass-ceramics and graphite. Within these substrates quartz is suited due to its resistant
to high temperature processes (≥1000°C) and allow the superstrate configuration for solar cell applications. Among
the different techniques, solid phase crystallization (SPC) of amorphous silicon is a promising approach to fabricate
high quality poly-Si thin films with the thickness of 2-5µm. The drawback of SPC is that larger grains require lower
crystallization temperatures, and hence, longer crystallization times. A novel crystallization technique is used in this
work to crystallize the amorphous silicon in shorter time resulting the larger grain size. Polycrystalline silicon thin
films were formed on quartz substrates by SPC of doped amorphous silicon (a-Si) deposited by electron beam
evaporation system. Then the samples were annealed by this novel a two-step annealing process which consists of
a low-temperature (≤500oC) classical furnace annealing for nucleation and a high-temperature (~1000oC) grain
growth process in classical furnace. The resulting SPC poly-Si layers were characterized using microscopical (optical
microscopy, electron backscatter diffraction (EBSD)) and spectroscopical (micro-Raman spectroscopy, X-ray
diffraction (XRD)). EBSD results depict that 2 times more enhancement in average grain size is achieved by using
novel crystallization technique when compared to conventional low temperature crystallization annealing
(≤500oC). A narrow and symmetrical Raman peak at a wave number of about 520cm−1 is observed for all samples,
which shows the fully and high quality crystallization. X-ray diffraction (XRD) reveals that the preferred orientation
of the films, independently from crystallization technique, is <111>. The results show that using the novel two-step
annealing technique improves the poly-Si thin film quality with larger grain size and lower defects.
Reza JALİLİ, Mete Çubukçu
Ege University Solar Energy Institute, TURKEY
Modeling and Control of Hybrid Wind- Photovoltaic Systems using PETRI networks
Electrical energy is an essential factor in development of human societies. Limitations of fossil fuels and their
instable price have led to remarkable increase of interest in renewable energy resources. In the present paper, an
electrical energy generation system consisting of wind turbine, solar (photovoltaic) panel, battery and diesel
generator is studied and modeled. Wind and solar energies are considered as the major energy generation
resources in the respective system. Yet, due to periodic characteristic of wind and sunlight, it is tangibly necessary
to store energy in ideal conditions for utilization in needed situations. In the current research, PETRI net is used as a
tool for intelligent implementation of strategy control in the electrical energy production systems. After introducing
system elements and concepts of PETRI networks, PETRI model is presented for each of elements and the
governing rules of the system. The ultimate goal of this modeling is to control a hybrid energy production system so
that electrical energy can be provided incessantly, and besides, maximal wind and photovoltaic power is utilized
during 24 hours.
100
Reza JALİLİ
Ege University Solar Energy Institute, TURKEY
Movable Photovoltaic Array for Enhancing Output Power of Photovoltaic Cells
Solar energy is a one of the available renewable energy forms which can be directly converted into electrical energy
using photovoltaic convertors. Photovoltaic convertors are among the favorable equipments in the scope of new
energies utilization due to the possibility of direct conversion of solar energy into electrical energy and other
advantages such as low weight and installation abilities in small powers. However, they are more expensive
compared to electrical energy convertors. Therefore, the circumstances must be provided to absorb maximal
energy from such convertors in order to have the optimal usage from the system. Sunlight always radiates at an
angle to the surface of solar arrays since sun moves during the day; accordingly, part of light is reflected from the
surface of photo cells preventing from complete absorption of sunlight. Application of movable solar arrays is a way
to enhance the output electrical energy in photovoltaic convertors. In this method, photovoltaic array is able to
follow sun movement all day long to absorb the maximal sunlight by photo cells and thus generate maximal
electrical energy through providing perpendicular incidence of solar beams on the array plane. The current paper
investigates the effect of applying movable photovoltaic array on increase degree of output power as compared to
a fixed photovoltaic array with identical nominal power. It is demonstrated in the present paper that use of
movable photovoltaic arrays is among the best exploitation states for photovoltaic convertors because of strong
dependence of the power generated by photo cells to the absorbed sunlight. The research results are indicative of
the fact that over 36% additional energy can be absorbed in a complete summer day in the case of using movable
photovoltaic array.
Zeynep DEMİRCİOĞLU, Engin ÖZKOL, Raşit TURAN
Middle East Technical University Center for Solar Energy Research and Applications (GUNAM), TURKEY
Optimsation of Laser Scribing of PET for Thin Film Module Formation
The third generation flexible thin film solar cells have its place with its improving efficiency in the PV market. In
order to have required or desired voltage and current values from a solar cell the formation of a module is used by
connecting each individual cell series or parallel. In the thin film case laser patterning is one of the most commonly
used methods for monolithic series connection. Module is obtained by three main scribing processes called P1, P2,
and P3. Each laser process takes place during the cell production. P1 is the removal of the transparent conductive
oxide (TCO) layer (After P1, p-i-n structure is deposited.). P2 is the removal of silicon layer up to the TCO layer (Back
contact is deposited after P2 process.). P3 is the removal of the back contact and the silicon layer up to TCO layer.
In this study monolithic series connection of a flexible thin film amorphous silicon solar cell was studied.
Polyethylene terephthalate (PET) substrate was used as a flexible substrate. The laser used for this study is a
nanosecond Nd:YAG laser with a motor controlled system. In order to obtain clear-cut lines, different laser and
motor control parameters such as laser frequency, laser power, and motor speed was investigated. Each scribing
parameter was studies separately. Optimized parameters for P1, P2, and P3 scribing for PET substrate are obtained.
101
Olgu DEMİRCİOĞLU, Fırat ES, Mustafa KULAKÇI, Raşit TURAN
Middle East Technical University Center for Solar Energy Research and Applications (GUNAM), TURKEY
Electroless Nickel Plating For Buried Contact Solar Cells
Buried contact solar cell (BCSC) design is one of the innovative approaches regarding to the crystalline Silicon (c-Si)
Solar Cells. Purpose of this design is increasing the aspect ratio of metal fingers on front surface and increasing the
contact area between metal and semiconductor material. In BCSC design, front metallization should be placed into
the grooves which are created by laser operation. Although screen printing method is the most common printing
method for solar cells, it is not suitable for BCSC design due to print alignment and filling of metal into the grooves
without any gap. Electroless plating is a good alternative to screen printing since it is self-aligned method and can
perfectly fill the grooves. Despite copper cannot be used in screen printing method, electroless plating enable to
usage of copper as front contact material. However diffusibility of the copper is too high and hard to control that in
high temperatures. Therefore electroless Nickel plating as a barrier layer should be created between copper and
silicon. In this study, electroless Nickel plating investigated for solar cell applications. Antireflection coating (SİNX)
used as plating mask and 11W 532nm nanosecond laser used for groove formation. Different groove geometries
are and laser parameters are studied and most efficient geometry obtained for homogenous Nickel plating.
Different plating solutions and conditions are also suited in this study. Importance of the HF percentage in the
solution and dependency of plating duration on the plating quality have studied. It is observed that SiNX on the cell
may be damaged during plating process. Reasons of this affect investigated and eliminated by optimization of
process parameters.
Mustafa KULAKÇI, Raşit TURAN
Middle East Technical University Center for Solar Energy Research and Applications (GUNAM), TURKEY
ZnO nanowire/CdTe heteojunctions for photvoltaic and UV photodetector applications
CdTe based thin film heterojunctions have been under intensive investigation over the last few years. This is mostly
due to the optimal physical properties of CdTe for highly efficient conversion of solar energy. Moreover, this
heterojunction thin films can be fabricated by a wide variety of scaleable techniques in a cost effective way.
Nowadays researchers have been intensively focusing on both increase of the efficiencies of conventional solar
cells and more affordable new solar cell materials or new heterostructures with superior performances under the
flourishing availability and flexibility of nanotechnology platform. In this presented study, ZnO nanowire/CdTe
heterojunction were fabricated as a proof of concept devices without optimization and intentional doping in
superstrate structure with and without CdS interlayer, and electrical and photoelectrical properties were measured
and evaluated. ZnO nanowires produced by hydrothermal method on glass covered with tin doped indum oxide
(ITO), CdTe and CdS flms were deposited by sputtering technique. Deposited films were treated with CdCl2 and
annealed at 430 oC to increase its crystallinity which is followed by oxide layer removal in bromine solution.
Antimony and gold evaporated for ohmic contact formation on CdTe top film and annealed at 150 oC. In the
electrical measurement it was found that, heterostructures are shows good diode behavior in both type of devices,
however interlayer CdS enhances diode properties. Moreover, CdS layer between ZnO nanowire and CdTe
significantly improve the solar cell device performances in all physical parameters (VOC, ISC, FF and efficiency), cell
performances were measured under AM1.5 condition. Besides the photovoltaic mode, the fabricated
heterojunctions could be switched from solar cell to UV photodetector under external biasing either reverse or
forward. Under UV photodetctor mode devices respond to only UV light (band edge of ZnO), i.e. our devices can be
modulated between solar cell and UV detector mode.
102
Faruk BALLIPINAR
Istanbul Technıcal Unıversıty Instıtute Of Energy, TURKEY
Inverted Bulk Heterojunction Organic Solar Cells on ZnO Nanostructures
Organic photovoltaics based on semiconducting polymers offer low cost, light weight and flexible alternatives to
inorganic photovoltaics Current state-of-the-art organic photovoltaics are based on a mixture conjugated polymer
as electron donors and fullerene as electron acceptors. In polymer solar cells, poly (3-hexylthiophene) (P3HT) and
phenyl C61-butyric acid methyl ester (PCBM) are generally the most common materials that polymer solar cell
efficiencies have been improved using P3HT:PCBM active layers. In normal type organic solar cells active layers of
P3HT:PCBM were fabricated between a transparent ITO (indium tin oxide) or FTO (fluorine tin oxide) and an Al back
electrode. These devices show instability due to rapid oxidation. To overcome this problem, inverted type bulk
heterojunction solar cells are developed. In this work, inverted type bulk heterojunction organic solar cells have
been fabricated using ZnO nanostructures such as nanoflower, nanorod, nanowire to investigate the performances
and energy efficiencies. Firstly the ITO glasses are patterned by etching with an acid of HCl. All ITO glasses are are
cleaned with acetone, methanol and distilled water for 5 minutes in ultrasonic bath. After cleaning process, the
growth of ZnO nanostructures such as nanoflower, nanorod and nanowire was carried out on ITO glasses by
hydrothermal method. In hydrothermal method, pH variation has an important role on obtaining different ZnO
nanostructures. With the different morphologies ZnO nano-architectures were constructed with average diameters
of 20-100 nm and lenghts in the range of 1-10 µm. We next generated inverted bulk heterojunction organic solar
cells on ZnO nanostructres. P3HT:C70 (polymer/fullerene) is dissolved in dichlorobenzene. The active layer is
deposited onto ZnO nanostructures by spin-coating process. In the same way, the other layer, PEDOT:PSS, being a
conducting polymer, is deposited onto active layer. To obtain anod electrod from ITO layer, PEDOT layer is
patterned with distilled water, followed by active layer is patterned with dichlorobenzene, then ZnO
nanostructures are patterned with acetone. Au electrode, being back electrod, was thermally evaporated at 10-6
mbar vacuum pressure. In summary, in this research the effencies of ZnO nanostructures in inverted type bulk
heterojunction solar cells are investigated. SEM (Scanning electron microscope) is used to observe film surface of
morphology of ZnO nanoparticles. Solar conversion efficiencies were investigated as depend on surface of ZnO
nanostructures. The best efficiency is obtained in inverted type bulk heterojunction solar cells of ZnO nanoflowers,
followed by ZnO nanowire, then ZnO nanorod structures. It is found that pH is critical parameter to obtain ZnO
nanostructures and efficient charge transfer. The important factor is ZnO nanostructure morphology for the
comparison of organic solar cell efficiencies.
103
Zeynep Deniz EYGİ, Mustafa KULAKÇI, Raşit TURAN
Canakkale Onsekiz Mart University, TURKEY
Effect of Growth and Post Annealing Temperature on the Crystallization Germanium Thin Films by
Electron-Beam Evaporation Technique: Role of Gold Nanoparticle layer
In recent years, low temperature deposited germanium thin films have gain attraction for solar cell applications.
Since the Ge has a low band gap, it is suitable for harvesting low energy photons in multi-junction tandem solar
cells. In addition, alloying with Si the bang gap of base material can be smoothly engineered from Si to Ge which is
crucially important for thin film Si solar cells. Furthermore, lower fabrication temperatures of polycrystalline Ge
thin films allow using low-cost and flexible substrates for large scale photovoltaic applications. Metal-induced
crystallization is a widely used method to form crystalline/polycrystalline structures at low temperatures. In this
work, Au was applied for enhance the crystallization of amorphous Ge films. Ge films with thicknesses of ~1.5µm
were fabricated by electron beam evaporation on Si substrates with and without very thin Au nano-particle layers.
Crystallization properties of amorphous Ge films were analyzed for different growth and post annealing
temperatures varies between 330 and 6500C. The structure and morphology of polycrystalline Ge films were
investigated by employing X-ray diffraction (XRD), Raman spectra, scanning electron microscope (SEM). It is
observed that existence of thin Au layer has a significant impact on the crystallization of amorphous Ge films in
terms of reducing the crystallization temperature. It was noticed that the impact of Au nano-particle layer on
crystallization slightly reduces at higher post annealing temperatures (above ~4000C), and almost any remarkable
differences has been observed between the fılms with and without Au nanoparticle layer. Raman measurements
showed that the growth temperature is more effective in crystallization than post annealing temperatures and also
in obtaining higher quality polycrystalline Ge films. At relatively lower temperatures, significant tensile stress has
been observed in deposited films, this stress released at higher growth and post annealing temperatures, whereas
any stress was remarkable in the films even at lowest temperature ranges. It is also observed that growth rate of
amorphous Ge films does not have a significant effect on crystallization or film quality.
İsmail KABACELİK, Raşit TURAN
Akdeniz University, TURKEY
Germanium Solar Cells Prepared by Ion Implantation
Development of Ge solar cells for multijunction solar cells, where the p-n junction is formed by ion implantation is
investigated. Ge samples are doped by phosphorus (P) ions having 60 keV energy at dose ratios of 1x1013, 1x1014,
1x1015 ve 1x1016 ions/cm2 at room temperature. The influences of P concentration and activation temperature on
Ge solar cells is investigated. P concentration and layer resitance are measured by secondary ion mass
spectrometry (SIMS) and a 4-point probe, respectively. Layer resistances of Ge samples is observed to vary as a
function of concentration and temperature. The short circuit currents (Isc) and open circuit voltages (Voc) of the Ge
solar cells is compared through examination of the I-V curves of the cells with respect to concentration and
temperature. Besides, a-Si thin films are introduced as anti-reflection coatings (ARC) via DC sputtering method and
the imact of ARC on Isc and Voc is investigated. The ARC is observed to increase the ISC’s of all four samples with
respect to uncoated samples.
104
İsmail KABACELİK, Mustafa KULAKÇI, Raşit TURAN
Akdeniz University, TURKEY
Ge Thin Films on Si Substrate for Photovoltaic Applications
Germainum (Ge) thin films possess an important potential in terms of reducing costs of photovoltaic devices,
especially multijunction solar cells. Ge thin films are grown over Si wafers at a thickness of approximately 250 nm
by means of E-beam method, while their structural properties are investigated by Raman and X-Ray Diffration
(XRD) spectrometers. Information regarding transition from the amorphous to the crystalline phase of the Ge thin
films as a function of temperature is collected from the Raman and XRD spectra of the samples. The films contain
both amorphous and crystalline phases simultaneously for annealing temperatures below 500 ˚C. The ratio of
amorphous to crystalline phase with respect to temperature is determined from the Raman spectra of as-deposited
films and those annealed at 300 ˚C and 400 ˚C. It is seen that the transition from the amorphous to the crystalline
phase is complete at an annealing temperature of 500 ˚C. The fact that Ge thin films with high crystalline quality
can be obtained at low temperatures suggests that Ge thin films can also be grown on Si and other substrates,
making them promising candidates for solar-cell applications.
Saime Şebnem ÇETİN, Tarık ASAR, Baris KINACI, Yunus ÖZEN, Tofig MEMMEDLİ, Süleyman ÖZÇELİK
Gazi University, TURKEY
Optical and Structural Properties of GaxIn1-xP Alloys Grown on Different Substrates
In recent progress, the GaInP semiconductor layers have been used for tandem solar cell application. The
knowledge about the critical point (CP) energies of the layers and the strain between the grown layers are
important to understand the band structure of samples. The GaxIn1-xP/GaAs and GaxIn1-xP/InP ternary alloys
were grown on SI-GaAs (100) and SI-InP (100) substrate by solid source molecular beam epitaxy (MBE) system using
GaP decomposition source. The range of lattice parameters in the epilayer and substrate composition in the
samples were determined from the high resolution X-ray diffraction (HRXRD) rocking curve simulation. The critical
point energies of the interband-transition edges of the structures were determined by line-shape analyses on their
dielectric functions using spectroscopic ellipsometry (SE) measurements at the room temperature in the 0.5-5 eV
photon energy region. In addition, band transition energies of the samples were determined by photoluminescence
(PL) emission spectra at the room. Acknowledgments: This work is supported by TUBITAK and DPT under the
110T333 and 2011K120290 project numbers, respectively.
105
Saime Şebnem ÇETİN, Kürşat KIZILKAYA, Süleyman ÖZÇELİK
Gazi University, TURKEY
Structural investigation and electronic band transitions of the TiO2 thin films
Titanium dioxide (TiO2) films have been used in several applications such as photocatalysts, anti-reflection
materials and dye-sensitized solar cells. TiO2 thin film was deposited on n-Si (100) substrate by reactive DC
magnetron sputtering system. The deposited film was thermally treated for 3 hours in the range of 400-1000 C by
conventional thermal annealing (CTA) in air atmosphere. The effects of the annealing temperature on the structural
and morphological properties of the films were investigated by X-ray diffraction (XRD) and atomic force microscopy
(AFM), respectively. XRD measurements show that the rutile phase is the dominant crystalline phase for the film
annealed at 800 C. According to AFM results, the increased grain sizes indicate that the annealing improves the
crystalline quality of the TiO2 film. In addition, the formation of the interfacial SiO2 layer between TiO2 film and Si
substrate was evaluated by the absorbance spectra obtained with FTIR spectrometer. The electronic band
transitions of as-deposited and annealed films were also studied by using photoluminescence (PL) spectroscopy at
room temperature. The results show that the dislocation density and microstrain in the film were decreased by
increasing annealing temperature for both anatase and rutile phases. Acknowledgments: This work is supported by
BAP at Gazi University and DKB under the 05/2010-65 and 2011K120290 project numbers, respectively.
Seçkin AKIN, Gamze KARANFİL, Aytaç GÜLTEKİN, Savaş SÖNMEZOĞLU
Karamanoglu Mehmetbey University, TURKEY
Synthesis and Surface Characterizations of CdS QDs doped CdO Thin Films for Photovoltaic Devices
In this work, CdS QDs nanoparticles used nowadays commonly in all areas as a new doping material, were doped
nano-structured CdO thin films. The characterizations of the morphological properties of the Cds QDs doped CdO
thin films have been carried out by means Scanning Electron Microscopy (SEM) and Atomic Force Microscopy
(AFM). From SEM images, the distinct variations in the morphology of the thin films were also observed. Atomic
Force Microscopy (AFM) analysis indicates that the CdS QDs concentration has a considerable influence on the
roughness of CdO surface. The obtained results show that CdS QDs as a doping material is an excellent candidate
for CdO based photovoltaic device applications.
Tarik ASAR, Baris KINACI, Yunus ÖZEN, Kürşat KIZILKAYA, Saime Şebnem ÇETİN, Tofig MEMMEDLİ,
Süleyman ÖZÇELİK
Gazi University, TURKEY
Investigation of the Photovoltaic Properties of InGaP/GaAs/Ge Solar Cells
Two InGaP/GaAs/Ge triple junction solar cell (TJSC) structures (GS244 and GS245) were succesfully grown by a solid
source molecular beam epitaxy (MBE) system. The structural properties of the structures were characterized by
high resolution XRD system. In addition, TJ solar cells on the square pieces (1 cm2) of the grown structure were
fabricated to determine the photovoltaic characteristics of these structures. Current - voltage (I-V) characteristics
of the each devices were performed and analyzed at the room temperature under both dark and illuminations by
using Keithley 4200 I-V measurements system and AM1.5 solar simulator. Acknowledgements : This work was
supported by SANTEZ under project No. 00587.STZ.2010-1
106
Gamze KARANFİL, Seçkin AKIN, Aytaç GÜLTEKİN, Savaş SÖNMEZOĞLU
Karamanoglu Mehmetbey University, TURKEY
Synthesis and Optical Characterizations of Au NPs doped CdO and TiO2 Thin Films for Solar Cells
Transparent Conducting Oxide (TCO) materials that have common applications area in optoelectronic devices, have
been widely studied in recent years. In the present study, pure and Au nanoparticles doped TiO2 and CdO thin film
have been synthesized using by sol-gel method and the effect of Au NPs doping on the optical properties of these
thin films was examined. In order to understand optical behaviours of the thin films, some optical parameters such
as transmittance (T), reflactance (R), extinction coefficient (k), refractive index (n) and band gap (Eg) were
investigated. The highest transparency values of pure TiO2, Au NPs doped TiO2, pure CdO and Au NPs doped CdO
thin films are 92.08%, 93.03%, 80.37% and 42.05%, respectively. The optical band gap of the as-grown TiO2 thin
films decreases from 3.60 to 3.57 and from 2.20 to 1.55 for CdO thin films with Au doping. Besides, it is found that
both extinction coefficient and refractive index of TiO2 thin film decrease with Au NPs doping, while increasing is
seen for CdO thin films with Au NPs-doped. These results provide some useful references for the potential
application of these thin films in especially in solar cells.
Süleyman ÖZÇELİK, Yunus ÖZEN, Saime Şebnem ÇETİN, Tarik ASAR, Nihan AKIN, Emine BOYALI, Gürkan
KURTULUŞ
Gazi University, TURKEY
Optical properties of ZnO thin film deposited on flexible-transparent substrate at room temperature
by DC magnetron sputtering
The films of ZnO deposited transparent flexible substrate can be widely used as an optical coating material and in
applications of light emitting diodes, lasers, sensor and solar cells as well as flexible electronics. In this study, ZnO
films were deposited on flexible-transparent substrate with different thickness by DC magnetron sputtering
technique. The structural and optical properties of the films were investigated by X-ray diffractometry (XRD),
photoluminescence (PL) and UV–visible spectrophotometer. Results revealed that the obtained film had a
hexagonal structure and a highly preferred orientation with the c-axis perpendicular to the substrate. The
electronic transitions from the conduction band to the valence band (band gap) of the films located at about 3.35
eV. It is observed that the exitonic transition energy of the ZnO film has blue-shifted to a high energy value with
increasing the film thickness. In addition, the films showed a high optical transmittance over 80% in the visible
region. Acknowledgements : This work was supported by DKB under project No. 2011K120290
107
Murat GURSOY, Tolga EROĞAN, Bülent AÇIKGÖZ, Pelin RODOPLU, Aslı SAVURAN, Muhyettın SIRER
UNDP, TURKEY
Strategy development on utilizing solar energy technologies as drivers of growth for the GAP Region of
Turkey
Turkey is located geographically in a region called the “solar band,” which has the greatest utilization potential for
solar energy. The GAP Region boasts the highest solar energy potential in the country with increased installed
capacity as a result of technological improvements, economies of scale, and volume production. For the credibility
of the Sustainable Growth Strategy for Southeastern Anatolia (GAP) Region of Turkey the use of solar energy is a
must. A regional growth strategy for the GAP Region based on utilization of appropriate solar energy technologies
is thus developed and introduced here. The aim of the strategy is to improve the Region’s economic
competitiveness through the development of a sustainable energy supply, mainly by solar energy. The framework
for the strategy consists of five stages: diagnosing the region, defining options, finding strategic solution
hypotheses, prescribing solutions, and creating implementation and evaluation strategies. The analysis of the
strategy suggests nine areas that reinforce the impact of solar energy development on the Region’s economic
competiveness: 1. Energy cost reductions will lead to lower overall costs in the Region and higher energy supply
security. The Region especially industrial sector which needs to increase its competiveness in world markets,
currently is burdened with high conventional energy costs. 2. The Region will achieve economic growth as a
producer of solar energy (SE) technology products. 3. Domestic as well as foreign producers of these technologies
will be attracted by the creation of early and ambitious demand within the Region for these solutions. 4. The
Region will establish an REEE Research Center, which will improve education, innovate new technologies, draw
investments, and help create partnerships, both with domestic and international firms and research centers. 5. The
Region will create new jobs in green tech companies, supported by relevant training programs. 6. By using the
irrigation capacity created by the investment in hydropower, very large tracts of de facto virgin land can become
arable, and a new sector in sustainable and organic agriculture can be developed. 7. Investments in SE will affect
the supply chain towards higher value-added goods, such as the textile industry, where organic cotton becomes a
starting point of a chain for the finishing of sustainable and organic textiles and garment products. 8. By moving
from “the cradle of civilization” to a leader in “the birth of sustainable civilization,” the Region will be able to
develop a differentiated and unique tourism industry. 9. In becoming the world’s first developing region that is
carbon neutral on a net basis, the Region will be able to develop a brand that will lend a competitive advantage to
all its industries and help generate both internal and external alignment around and recognition of the strategy. It is
expected that framework of the strategy outlined here can be a useful tool for any other developing regions of the
world.
108
Sadrettin KARAHOCAGİL, Mustafa KÖLMEK, Nusret MUTLU, Yılmaz DAĞTEKİN, Muslum ALTUN, Burak
R. SAT, GAP REGIONAL ADMINISTRATION, TURKEY
Pilot project studies on utilizing solar energy technologies as drivers of growth for the GAP Region of
Turkey
Turkey is located geographically in a region called the “solar band,” which has the greatest utilization potential for
solar energy. The GAP Region boasts the highest solar energy potential in the country with 1460 kWh/m2 and
sunshine duration of 2,993 hours, both per year. There are many solar technologies in the market that need to be
considered for the GAP Region. The intended application is an important factor when selecting one of these
technologies because they are intended for different scales. The Region has a high solar energy potential, especially
in the provinces of Şanlıurfa and Gaziantep, where the insolation incident is highest, and technologies where direct
solar irradiance is necessary can be developed. On the other hand, other solar technology does not need as much
direct solar irradiance, opening the possibility for the rest of the Region to take advantage of solar power. Turkey
and the Region are also rich in manufacturing industries that apply processes similar to the construction of thin
films and dye-sensitized solar cells, making this technology suitable for local production, and is the ideal technology
for solar irrigation pumps and other small-scale activities. The Region is also well positioned to deploy solar water
heating technology in low temperature heat using industries such as textile and food and also building heating and
cooling. Although there are European competitors who are also trying to attract investments into renewable
energy markets, thus making it harder for investors to focus on Turkey’s resources, the GAP Region has the best
solar resource of the country and one of the best in Europe. A pilot project implementation program for the GAP
Region to exploit utilization of appropriate solar energy technologies is developed and introduced here. Potential of
various solar energy technologies for contributing energy solutions, financial growth and job growth is assessed.
Main targets of this implementation program on behalf of the GAP Region are; 1. To become a leader amongst
developing regions in solar energy 2. To lead to lower overall energy cost in the region 3. To achieve economic
growth as producer of solar energy technology products 4. To establish a Research Center in the Region that builds
the capacity for world class research and development and education related to solar energy technologies 5. To
start early initiatives such as some government action, initiatives, seed funding, coordination, and flexibility,
proactive and targeted programs in workforce training etc. 6. To develop the use of solar energy technologies in
the region not only in the energy sector but also agriculture, textile and tourism, communication and brand
strategy. The potential pilot projects on solar energy technology area are evaluated under the following criteria: •
Any pilot must address solar energy opportunity for which demand either already exists or can be created in the
Region (ideally a demand that has characteristics that are differentiated from the present global market, while
being similar to the demand in other developing or geographically adjacent regions). • The pilots have to be
undertaken in cooperation with a partner that can supply the technology and who is willing to work with the
government and/or local business partners to establish – in many cases gradually – local production of the
technology, initially for the regional market, but over time also for adjacent markets. • Both the net energy
contribution and the potential for job creation have to be real and measurable. • The risk profiles of the
undertaken pilot activities have to be mixed and manageable, both in terms of technology risk (how proven is the
technology) and business risk. • Priority should be given to pilot activities that are commercially viable and that can
be scaled, that are best suited to demonstrate and prove the model of demand-driven innovation and job creation,
and that will help gain experience that can help improve the selection, planning and execution of later, larger scale
activities. Three pilot projects on solar energy technology are found to be appropriate. These pilot projects are;
Solar powered irrigation pumps, Solar heating for industrial process and Solar cooling and air-conditioning systems
(a/c) in hotels and public office buildings. Technical, financial, business and employment aspects of these pilot
projects are evaluated and the results obtained are presented here. It is expected that selection and
implementation methodology outlined here can be a useful tool for any other developing regions of the world.
109
ERCAN YILMAZ, Aleksandar JAKSIC, Aliekber AKTAG
Tyndall National Institute, IRELAND and Abant Izzet Baysal University, TURKEY
Structural and Electrical Characterization of BiFeO Thin Films as New Photovoltaic Materials
Ferroelectric materials have very high photovoltaic responses to illumination, but the mechanism has been
unknown yet [1]. Some new researches describe a model for the high voltages seen in thin-film bismuth ferrites
(BFOs), which may provide some insight to developing more efficient PV materials. BFOs themselves are not
candidate PV materials because they respond only to a very small slice of the solar spectrum (blue and near
ultraviolet). BFO thin films have a highly periodic domain structure (regions where the electrical polarization orients
in different directions). When illuminate the BFO thin films, very large voltages can be obtained, many times the
band gap of the material itself. The voltage have been measured across the film increased as the number of
domains between electrodes increased, showing researchers that somehow the domain walls were involved. In the
charge-transport model, picture of how each of the oppositely oriented domains creates excess charge and then
passes it along to its neighbor. The opposite charges on each side of the domain wall create an electric field that
drives the charge carriers apart. On one side of the wall, electrons accumulate and holes are repelled. On the other
side of the wall, holes accumulate and electrons are repelled. While a solar cell loses efficiency if electrons and
holes immediately recombine, that can’t happen here because of the strong fields at the domain walls created by
the oppositely polarized charges of the domains. Holes and electrons move away from the domain walls in opposite
directions, toward the center of the domain where the field is weaker. Because there’s an excess of electrons over
holes, the extra electrons are pumped from one domain to the next - all in the same direction, as determined by
the overall current. It’s like a bucket brigade, with each bucket of electrons passed from domain to domain. As the
charge contributions from each domain add up, the voltage increases dramatically. The mechanism will apply to all
materials with “sawtooth” potentials, which opens the possibility of developing new PV materials with high voltage
and high current. Under the light of this information, we aim to deposit BiFeO3 thin films and obtain deep
information in details about BiFeO3 material. In this work, BiFeO3 thin films were deposited on p-type Si substrate
at 0 0C by RF magnetron sputtering. Samples were annealed at 550 0C for 30 minutes in atmospheric environment.
The structural and electrical properties of both as-sputtered and heat-treated samples were investigated. Results
show that the formation Nano crystals were observed after annealing. Interface density, effective charge carriers,
and equivalent oxide thickness were calculated as 3.4x1012 eV-1cm-1, 1.34x107 qcm-2 and 205 nm respectively
from CV characteristic of MOS capacitor. The obtained results were discussed in correlation with the structure of
the films.
110
Bader El-Din Mohamed Ali, Mohamed A. Kotb, Adel A. Banawan, Amr A. Hassan
AASTMT, EGYPT
Utilization of Solar Energy in Inland Water-Way Units
The world faces a challenge on energy; energy resources such as fossil fuels are getting scarcer and instability. The
continuous increase in the consumption of the fossil fuels pollute local and global environment and the public
demand environmentally friendly energy for all walks life sectors. The earth receives an abundant amount of the
renewable solar energy from the Sun. The Middle East region is rich with solar energy, and Egypt is located in the
Sunbelt Solar energy area. In addition, the solar resources on Upper Egypt are excellent; the Upper Egypt cities
"Luxor & Aswan" are located in the strongest solar density area and most powerful in the world throughout the
year. There are a large number of luxury cruise ships sailing between Cairo to Luxor and Aswan and vice versa (Nile
Cruise) about 300 Nile cruise ships (large floating hotels) in addition to about 50 heritage, majestic and historical
boats are famous by a common name known as "Dahabiyya". This paper focuses on the exploitation of the of solar
energy for the inland water-way Nile Cruise units through experimental study and numerical analysis using
Computational Fluid Dynamics (FLUENT code) to simulate, demonstrate and investigate thermal heat energy and
other parameters for the hybrid photovoltaic / thermal (PV/T), which consist of photovoltaic (PV) modules for
electric loads plus thermal units under the (PV) modules to absorb excess heat generated and protect (PV) module
efficiency drop.
Hakan BİLGİLİ, Sermet Koyuncu , Burak Gültekin, Şerafettin Demiç, Sıddık İçli
Ege University Solar Energy Institute
Synthesis of Novel Donor-Acceptor Type Polymers for Organic Photovoltaics
Organic Photovoltaic (OPV) research has attracted scientific and economic interest triggered by a rapid increase in
power conversion efficiencies. This was achieved by the introduction of new materials, improved materials
engineering, and more sophisticated device structures. Despite the inorganic materials, organic materials are
abundant and easily handling. Unfortunately OPV cells efficiency is significantly lower than that of inorganic-based
devices, representing a big point of weakness at the present. This is mainly due to the fact that organic
semiconductors have a much higher band gap with respect to inorganic semiconductors [1]. In addition, OPV cells
are very sensitive against oxygen and water [1]. It is well documented by many groups that OPV devices fabricated
using poly(3-hexylthiophene) (P3HT) donor and [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) acceptor gives
power conversion efficiencies (PCE) about 5% [2]. There are several groups worldwide working on developments of
new low bandgap donor polymers to enhance PCE further up to 10% using PCBM acceptor [3]. In this study, we
present two new donor-acceptor type co-polymers based on S-N-S (thiophene-pyrol-thiophene) and
benzothiadiazole/ benzoselenadiazole to use as donor materials in bulk heterojunction type organic photovoltaic
cells. The photopysical and the electrochemical properties of the polymers have been determined by UV-Vis,
Fluorescence Spectroscopy, and Cyclic Voltammetry. Bulk heterojunction type organic photovoltaics have been
fabricated and the synthesized polymers have been used as donor. The photovoltaic performance measurements
have been carried out under standard conditions while P3HT/PCBM has been used as the reference. References 1)
G. Chidichimo and L. Filippelli, International Journal of Photoenergy, Volume 2010, Article ID 123534 2) W. Ma, C.
Yang, X. Gong, K. Lee and A. J. Heeger, Adv. Funct. Mater., 2005, 15, 1617 3)
http://www.konarka.com/index.php/site/pressreleasedetail/konarkas_power_plastic_achieves_world_record_83_
efficiency_certification_fr
111
Mahmut KUŞ, Faruk OZEL, Nurhan Mehmet VARAL, Canan BAŞLAK, Yunus ÇENGELOĞLU, Mustafa
ERSOZ
Selçuk University, TURKEY
Colloidal Quantum Dot Based Organic-Inorganic Hybrid materials for QDSSC
Semiconductor quantum dots are considered to be a new class of materials with excellent optical and electronic
properties depending on their crystal size. Colloidal synthesis of quantum dots seems to be best way to fabricate
stable and fine crystals. In addition surface defects, which are important problem for such materials, may be
eliminated by colloidal route. On the other hand, the nature of capping agent is another key parameter for colloidal
quantum dots. Hydrocarbons such as oleic acid or TOPO and organic acids such as mercaptopropionic acid are
commonly used as capping agent. But these materials, due to their nature, are not proper surfactants for electronic
application. In this study we focused to synthesize proper organic-inorganic hybrid system for electronic
applications. Conjugated polymers, dendrimers or electron rich small molecules have been considered as proper
capping agent for QDSSCs. The interaction between nanocrystal core and capping agent has been investigated.
Sinan GÜNDOĞDU, Emel Sungur ÖZEN, Serim İLDAY, Karl-Heinz HEINIG, Raşit TURAN, Atilla AYDINLI
Bilkent University, TURKEY
Si Nanocrystal Networks by Si/SiO2 Phase Separation in SiOx Thin Films for Third Generation Solar
Cells.
Si/SiO2 phase separation in Silicon rich oxides is a very promising synthesis process of novel nanocrystaline Si (ncSi) structures for 3rd generation thin-film solar cells. The incorporation of larger band gap nanocrystaline silicon
into the solar cell structure can be utilized to improve the single band gap silicon solar cells efficiency by allowing a
better use of the solar spectrum. We present cw laser annealing of Si-rich oxide thin films with varying Si content to
obtain nc-Si embedded in silica. Silicon nanocrystals in the form of a nanocrystaline network (sponge-like) are
particularly interesting for their percolated structure. Calculations show that considerable Si band gap widening
due to quantum confinement in the nanocrystals network is expected. Beside this wide band gap, sponge-like Si
has another potential advantage of suppressing the carrier recombination loss mechanism by electrically
percolated nanostructures. SiOx thin films with x<2 were obtained by plasma enhanced chemical vapour deposition
(PECVD). Hydrogen or nitrogen diluted silane (SiH4) gas was used as the Si source and two different precursor
gasses, N2O and CO2, were used for oxygen incorporation. Fine tuning the Si excess in SiOx and optimizing the
annealing conditions is pursued to control the inter-nanocrystal distance to generate a network of Si nanocrystals.
The network formation depends critically on the precise control of composition during deposition. In the case of
SiOx films, it is expected that the network is formed upon phase separation when the stoichiometry parameter of
the initial SiOx film is x ~ 1 [1]. Nevertheless, in the case of PECVD grown Si-rich oxides, different elements such as
nitrogen, carbon and especially hydrogen can be present in the films. A detailed elemental study has been
performed to determine the precise composition of the films using ion beam techniques as elastic recoil detection
analysis (ERDA) and Rutherford back scattering (RBS), as well as X-Ray photoelectron spectroscopy (XPS), Fourier
transform infrared spectroscopy (FTIR) and ellipsometry. The presence of hydrogen in PECVD grown samples makes
ERDA an essential technique for compositional analysis although it is an expensive and hard to reach method. We
have compared the ERDA data of different sets of samples with XPS, FTIR and ellipsometry analysis within the
scope of listing a number of correlations between them and, further to be able to obtain the compositional
information with these more accessible techniques. After the characterisation of the as-grown samples, the role of
the composition in phase separation, as well as the laser irradiation parameters have been investigated and
hydrogen has been identified as a key parameter for the Si/SiO2 phase separation. This research is supported by
BMBF-TÜBITAK project "RainbowEnergy". [1] T. Muller et al, Applied Physics Letters, 85, 2373 (2004).
112
Vasfi Günhan KAYTAZ, Emir AYDAR, Emre BİÇER, Haydar LİVATYALI, Daniele M. TRUCCHI, Emilia
CAPPELLI, Alessandro BELLUCCI
TUBITAK Marmara Research Center Energy Institute, TURKEY
Analytical and Numerical Modeling of a Thermionic - Thermoelectric Concentrated Solar Conversion
Module
An innovative, cost-effective, reliable, scalable and efficient thermionic-thermoelectric system that turns
concentrated solar radiation into electric power is the main goal of the FP7 E2PHEST2US Project. A parabolic dish
reflector is used to concentrate direct irradiance over the conversion module (CM) that operates at 800 – 1000 °C
and generates DC current by thermionic and thermoelectric conversion stages thermally combined in series as well
as heat at the final stage. A quasi two-dimensional analytical model of the CM has been proposed. The solar
irradiance naturally available at Rome (Italy) and Tel Aviv (Israel) is concentrated over a quartz window that isolates
the thermionic disc kept under vacuum conditions. The analytical model is based on Fourier’s steady state heat
conduction, and the convection heat transfer at a Peltier port is modeled using finite volume method. Accordingly,
the expected temperature levels at the three stages of the conversion module have been predicted as reasonable
and achievable with the available concentrating direct irradiance.
Salar HABIBPUR SEDANI, Mehmet KARAMAN, Kadir ERTÜRK, Raşit TURANMiddle East Technical
University Center for Solar Energy Research and Applications (GUNAM), TURKEY
The Electrical Properties of Effusion Cell Doped Silicon Thin Films; Towards a Low Cost Fabrication
Method for Silicon Based Solar Cell Applications
In the case of photovoltaic applications, thin film amorphous and crystalline silicon fabricated on glass substrates
role a great foreseen potential. The amorphous silicon was doped by boron and phosphorus direct evaporating
with using of specially designed effusion cells. In this study, the electronic properties of e-beam evaporated and sodeposited amorphous silicon doped or undoped films are discussed as the matter of dependence on the various
temperatures of effusion cells. In the case of a constant rate for silicon deposition, phosphorus was evaporated
between 600 °C and 800 °C simultaneously or so for boron but between 1600 °C and 1800 °C. The thickness and the
band gap of films were determined by ellipsometry method and the results were compared for effusion cells’
different evaporation temperatures. The mobility of carriers and the active dopant amount in the films measured
by the I-V and the Hall Effect measurements. We do repeat all the measurements again after a three steps process
that known as a usual solar cells preparing process include; 24 hour annealing in furnace under nitrogen flow in
600oc, additionally annealing in Rapid Thermal Annealing instrument at 900oc for just 4 minutes while and lastly
hydrogenating in 650oc for 20 minutes.
113
Mehmet AYDIN, Mehmet KARAMAN, Kadir ERTÜRK, Raşit TURAN
Namık Kemal University, TURKEY
Crystallization of Amorphous Silicon by Using Gold Colloidal Solution
Thin film crystalline silicon has great importance for electronic industry. Its’ easy and low cost production on glass
at low temperatures is an advantage for photovoltaic applications. In this study the crystallization of amorphous
silicon by gold nanoparticles was studied. Electron beam evaporation technique was used for amorphous silicon
deposition. The crystallization process was accomplished by gold nanoparticles which induces the crystallization
during the heat treatment. Gold colloidal solution, which contains nanoparticles in the range of 5-20 nm, was
dripped onto amorphous silicon. The sample was heated on hot plate to evaporate the solvent. The amorphous
silicon with remaining metal nanoparticles was annealed in a classical furnace for crystallization. The crystallization
duration was investigated with respect to different annealing temperatures. Raman measurements confirmed the
crystallinity of the samples and the crystalline amount was examined by Peak Fit analysis. The different crystalline
orientations was observed by X-Ray analysis.
Nese Kavasoğlu, Atilla Eren Mamuk, Murat Kabakci, Abdulkadir Sertap Kavasoglu
Mugla Sitki Kocman University, TURKEY
Determination of electronic parameters of Ag/SnO2/p-Si/Ag structures
Transparent conductive oxides have prompted as much interest as transparent conductive oxides due to their
valuable properties such as high optical transparency in the visible region and low electrical resistivity. Towing to
these properties, transparent conductive oxides are very useful in such applications as solar cell technology, gas
sensors, and transistors and also in a wide variety of electronic applications. It is very important to know physical
properties of the thin film layers in the the devices for optimization of electrical and optical properties. In this
study, we fabricated transparent conductive oxide film SnO 2 on p-Si substrates by sol-gel method. Current-voltage
characteristics of Ag/SnO 2 /p-Si/Ag structures exhibit diode behavior at different temperatures. Electronic
parameters are determined by using measured current-voltage data.
Sara El-MOLLA, Asmaa Fahiem MANSOUR, Mohammed GABR
Faculty of Science, Zagazig University, EGYPT
Enhancement of fluorescence and photo stability based on interaction of fluorescent dyes with Silver
nanoparticles for luminescent solar concentrators
Silver nanoparticles (NPs) were characterized by X-ray diffraction (XRD) and UV- Vis absorption spectra. UV-Vis
spectrum showed a single peak at 442 nm due to the surface Plasmon resonance (SPR). Position of SPR peak
exhibited a red shift after the sample was exposed to UV irradiation (unfiltered light). The optical band gap values
have a reduction from 2.46 to 2.37 eV after irradiation for 960 minutes. Such reduction in optical band gap may be
due to change in particle size which calculated using Mie theory. For Luminescent solar concentrators (LSC), it is
important to enhance the fluorescence quantum yield (FQY) and photo stability. Our measurements have
demonstrated that the addition of Silver nanoparticles to dye solution causes broadening of absorption bands, so
the spectral range of sunlight absorbed by LSC has increased. The photo stability of organic dyes used was
improved after adding Silver nanoparticles. The area under fluorescence spectra of dyes with Silver NPs increased
by 41-31 % when compared with identical dye concentrations without Silver nanoparticles as a result of interaction
of the species with Silver NPs.
114
Reza Jalili, Mete Çubukçu, Melih Soner Çeliktaş, Günnur Koçar,
Solar Energy Institute of Ege University, Ege University, Izmir-Turkey
Technology Roadmap for Photovoltaics
Technology roadmap is an important tool for collaborative technology planning and coordination actions for
corporations, industry, civil society, universities as well as for all policy makers. A technology roadmap matches
short-term and long-term goals with specific technology solutions to meet identified plans. The technology
roadmapp process consists of three phases; preliminary activity, development of the technology roadmap and
follow-up activity. It also provides information to make better technology investment decisions by identifying
critical technologies, technology gaps and ways to leverage R&D investments. It can also be used as a marketing
tool. Technology roadmap is generally used when the technology investment decision is not straight forward.
In this paper most common published PV Roadmaps and articles were processed in systematically. This study is
focusing on the PV energy technologies which will be available in the next decades and attempts to review and
analyze strategic technologies. The objective of the study is to describe trends in the development of PV energy
technologies, to highlight R&D priorities and critically discuss the data gathered from foresight studies of various
industrialized countries.
115
Sponsors:
Institutional Supporters