Sensitive materials - Institut de Chimie de la Matière Condensée de

Application-focused photonics
AMOS
Assistant Professor Veronique Jubera describes the goals and context of the AMOS project, explaining
the methods and tools used to elucidate the functional potential of a range of candidate compounds
Could you first introduce the Advanced
Materials for Optical Sensors (AMOS)
project’s context within photonics? How
did this research proposal come into being?
How do you investigate the ways in
which inorganic materials react with the
environment?
Semiconductors such as ZnO or TiO2 present
really interesting photocatalytic activity. For
instance, degradation of solvents is a challenge
for domestic application, and to quantify this
activity is not easy. In our consortium, one of
our partner specialists in photocatalysis (IPREM,
Pau) has the task of evaluating this property.
The AMOS programme forms a foundation for
the development of innovative sensor devices.
The sensing systems have to be compatible
with distance testing, keeping the excitation
and detection system out of the sensing zone.
Advantages are that they are compatible
with on-board technology and represent a
compact and robust system, due to the fact
that multiple light sources and detectors are
now available.
Our technology is based on the use of specific
materials subjected to selected atmospheres
or temperatures. Under irradiation, these
factors can induce modifications of the
optical properties of those materials.
By consequence, the specific surface
and morphology of materials becomes
a predominant criterion for controlling
luminescence properties. Luminescence
is not recorded simply for spectroscopic
characterisation, it can be useful as a
diagnostic tool to follow and control lightinduced modifications of the materials.
The AMOS project has the aim of
investigating the luminescence
properties of inorganic materials under
different external stimuli that could be
modifications of their environments,
eg. atmosphere and temperature. The
influence of defects generated at the
surface (comparing several morphologies
of semiconductor nanoobjects) or related
to the composition (understanding redox
phenomena as a function of temperature)
is highlighted. Such topics will be central
to the development of innovative sensor
devices based on photonic properties and
possessing the capability of being sensitive
to external modification of the environment
(chemical compound, temperature).
What have been the outcomes of
previous programmes devoted to optical
applications at the University of Bordeaux?
The AMOS project in the Aquitaine region
benefits from the surrounding dynamic,
Detecting an optical response is simpler
and more immediate. To correlate emission
intensity to a level of solvent degradation, to the
atmosphere or thermal exposure could allow
rapid control of a component during machining.
including Advanced Materials in Aquitaine
(AMA), the EU project Functionalised
Advanced Materials and Engineering of
Hybrids and Ceramics (FAME) and nowadays
the center of excellence Laser and Photonics
in Aquitaine (LAPHIA), part of the Initiative
d’excellence (Idex) of the University of
Bordeaux. Thanks to those programmes, the
Bordeaux site gathers different expertise
in science but also strong international
education programmes which feed each other
in order to provide the best environment
for discoveries. Such a place is also highly
appropriate for educating and preparing
younger generations for the promising field
of photonics.
How will AMOS build on previous findings?
Every project is based on the knowledge
acquired from previous studies. This can be
the discovery of an innovative composition,
an original synthetic route or a peculiar
property of the effect of shaping. Preliminary
studies evidenced the need to gather several
skills to fully understand the behaviour
of nanomaterials under irradiation. Our
team is at the forefront of research on the
relationship between catalytic properties
of TiO2 and luminescent properties with
the scope of developing innovative sensing
materials. To associate an optical response to
a secondary property appears to be a good
opportunity for investigate applications such
as sensors.
Can you give an insight into the types of
methods and tools you are using? Has your
lab developed any novel techniques?
The skills represented within our consortium
are complementary. At ICMCB, some of
my colleagues have developed innovative
syntheses to obtain nanomaterials by using
supercritical fluids. We also benefit from an
important department which conducts crystal
growth, making it possible to obtain massive
materials. In AMOS, we have successfully
grown a crystal that presents optical instability
and thermal hysteresis under irradiation.
All these materials can be characterised by
luminescence spectroscopy, under controlled
atmospheric conditions and temperatures,
and microluminescence which reveals local
perturbations of optical properties.
How important is scientific dissemination
to your research? What channels do you
use to share your findings with the scientific
community?
Each result is important but it is only useful
to the scientific community if published. Oral
communications, articles and posters are also
traditional ways to disseminate results. This is
good way to gain visibility in our research area.
But the danger today is to favour quantity over
quality when it comes to communication. As
a Maître de conferences at the University of
Bordeaux, it is also important for me to
sensitise students to local and international
research activities.
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AMOS
Optical fingerprints – the future for sensors?
A large and multidisciplinary research team is working to elucidate the optical properties of inorganic
materials, focusing on changes that occur in optical signatures of inorganic materials when exposed to
different environmental stimuli such as temperature and atmospheric composition. Such knowledge could
enable the production of a range of important technologies, including sensory and medical devices
TODAY, THERE IS growing recognition that we
do not fully understand the characteristics of
many inorganic materials. As such, technological
progress can be limited by the availability of
materials with suitable properties for certain
applications. In order to plug this gap, many
nations are investing in and encouraging research
into inorganic material behaviour.
assessment of their suitability for potential
applications such as sensors and medical
devices: “The goal is to bring expertise in the
field of sensing materials based on luminescent
properties to the academic community and
larger society,” expands Jubera.
A large French consortium is currently
investigating and characterising a range of
inorganic materials with the aim of providing
the knowledge required to enable further
technological development in a wide range of
applications. Within this consortium sits an
important project called Advanced Materials
for Optical Sensing (AMOS). AMOS is working
to elucidate the optical properties of a range of
inorganic materials under various environmental
conditions. Led by Assistant Professor Veronique
Jubera, the group is analysing the optical
properties of these compounds – providing an
Within their remit, the French team working
under the AMOS umbrella is focusing on
inorganic materials which have the potential to
modify their optical properties in a predictable
and reversible manner. Crucially, if the optical
fingerprints of inorganic materials can be
controlled by factors such as temperature, then
those materials could be employed in a range of
devices. “Transition between energy levels under
excitation results in emission in the ultraviolet,
visible or infrared range that can easily be
recorded with commercial detectors,” Jubera
explains. Candidate materials include metallic
AMOS OPPORTUNITIES
cations such as rare earth or transition metals,
which possess optical fingerprints that may be
both useful and controllable.
Controlling and understanding the morphology,
surface or oxidation state will be the primary
challenge in AMOS. Another critical challenge is
establishing how the candidate materials behave
when exposed to the atmosphere. If the active
materials degrade over time due to oxidation
or other reactions at the material-atmosphere
interface, then their usefulness will be limited.
As such, the team is working to elucidate the
optical behaviour of candidate materials over
long periods of time alongside their short-term
responses to environmental change.
Alongside environmental temperatures, AMOS
scientists are also keen to examine changes in
optical properties of materials in response to
different gases: “A systematic study will be carried
out on the kinetic behaviour of the luminescence
The French team working under
the AMOS umbrella is focusing on
inorganic materials which have the
potential to modify their optical
properties in a predictable and
reversible manner
RARE EARTH DOPED MATERIALS.
Explanation: Optical materials are synthesized as nano
and micrometric powder and massive materials as single
crystals materials at ICMCB
94INTERNATIONAL INNOVATION
INTELLIGENCE
AMOS – ADVANCED MATERIALS FOR
OPTICAL SENSORS
OBJECTIVES
To investigate the relationship between
luminescence properties of inorganic materials
and external stimuli, such as modifications of
their environments. This research will form the
foundations for developing innovative sensor
devices based on photonic properties, possessing
the capability to be sensitive to external
modification of the environment.
Experimental setup used to characterize luminescent materials at ICMCB.
and the reversibility of the process in different
gaseous media,” adds Jubera.
Armed with core knowledge regarding the
optical responses of inorganic materials to
environmental stimuli such as temperature and
atmospheric composition, and the resistance of
those responses to the degradation of the active
materials, Jubera and colleagues will be able
to begin creating prototype devices: “Device
configuration will be carried out to demonstrate
the feasibility and proof of concept of such an
innovative approach”.
THE IMPORTANCE OF THE PAST
The French team also want to illustrate the
ability to control optical fingerprints by altering
the synthetic process used to create those active
materials. The optical properties of candidate
materials are not always fixed. By altering the
synthesis process, the group has been able
to create materials with unusual properties
relative to their more ‘natural’ counterparts,
as Jubera elaborates: “ For instance, it has been
possible to obtain zinc oxide nanoparticles with
a unique ultraviolet emission through an original
supercritical fluids route”.This work, accomplished
by AMOS subgroups based in Bordeaux, has been
echoed by their colleagues in Toulouse, who have
managed to create nanoparticles with high visible
emissions by employing a novel organometallic
synthesis method. In combination, these two
results showcase the team’s ability to modify
the optical output of inorganic compounds by
altering production methods.
COLLABORATION IS KEY
Due to the complexity of the science and the
necessity of utilising a variety of skills within the
AMOS project, the French consortium consists
of four key collaborating organisations with
diverse expertise: the Institut de chimie de la
matière condensée de Bordeaux (ICMCB), which
specialises in solid-state chemistry and materials
science; Laboratoire de chimie de coordination
(LCC) in Toulouse, whose expertise lies in
nanostructures and organometallic chemistry;
Institut Pluridisciplinaire de Recherches sur
l’Environnement et les Matériaux (IPREM),
focusing on novel hybrid photocatalytic
materials; and finally, Laboratoire de l’Intégration
du Matériau au Système (IMS) from Bordeaux,
with a specialism in microsystem design and
application.
In combination, these partners create a
formidable research collaborative, capable of
the efficient and rapid advancement of inorganic
materials research. One of the key benefits that
such collaboration provides is strength and
depth of expertise: “Our strength remains the
capability to gather together material synthesis,
materials shaping, luminescence properties,
analysis of photo-produced species and material
characterisation expertise,” underlines Jubera.
Critical to the success and maintenance of such
a large network is the funding provided by the
Agence Nationale de la Recherche (ANR), Pôle
de compétitivité ‘Route des lasers’, and similarly
the support provided by the Aquitaine Region,
CNRS and University of Bordeaux, particularly
concerning the group’s work with photonics.
A GOLDEN AGE
Materials science is experiencing a golden age
of R&D. Rapid advances in modern technology
are influencing a range of scientific and technical
research areas. As the devices of the modern
world become more complex, and in many
cases more compact, the functional components
which constitute those devices become
correspondingly more complex. As such, many
countries are investing in research into the
suitability of a range of inorganic materials for
various technologies.
The AMOS group represents one of the most
globally important examples of this enterprise.
Focusing on the optical properties of inorganic
materials, Jubera’s team is illustrating the
untapped potential of many luminescent
compounds. By characterising the optical
fingerprints of candidate compounds in
response to differing environmental factors, the
researchers have shown the theoretical ability
of these materials to be used in components
of future devices. Furthermore, by measuring
the impact of material ageing processes on the
optical fingerprints of candidate compounds and
creating synthesis methodologies which produce
controllable properties, the group has taken the
theoretical application of these compounds and
illustrated the very real feasibility of such devices.
PARTNERS
Institut de chimie de la matière condensée de
Bordeaux (ICMCB)
Laboratoire de chimie de coordination (LCC),
Toulouse
Institut Pluridisciplinaire de Recherches sur
l’Environnement et les Matériaux (IPREM), Pau
Laboratoire de l’Intégration du Matériau au
Système (IMS), Bordeaux
FUNDING
Agence Nationale de la Recherche (ANR), Pôle
de compétitivité ‘Route des Lasers’.
CONTACT
Assistant Professor Veronique Jubera
Principal Investigator
ICMCB – CNRS
UPR9048
87 Avenue du Docteur Schweitzer
33608 Pessac cedex
France
T +33 5 4000 3703
E [email protected]
www.agence-nationale-recherche.fr/
programmes-de-recherche/recherchesexploratoires-et-emergentes/blancgeneralite-et-contacts/blanc-presentationsynthetique-du-projet/?tx_lwmsuivibilan_
pi2%5BCODE%5D=ANR-10-BLAN-0820
ASSISTANT PROFESSOR VERONIQUE
JUBERA has been Maitre de conférences at
the University of Bordeaux since 2002 (PhD in
materials science and solid state chemistry in
2001 and Habilitation in 2012). Her research
interests are dedicated to the discovery,
structural and luminescent characterisations and
applications of novel optical materials based on
rare earth and transition metal properties.
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