Supporting Information

Supporting Information
Waterproof Alkyl Phosphate Coated Fluoride Phosphors for
Optoelectronic Materials
Hoang-Duy Nguyen, Chun Che Lin, and Ru-Shi Liu*
anie_201504791_sm_miscellaneous_information.pdf
Supporting Information
1. Package test
The commercial YAG:Ce3+ (Chi Mei Corporation, Taiwan) yellow phosphor or -SiAlON:Eu2+
(Denka, Japan) green phosphor, prepared K2SiF6:Mn4+ red phosphor, and blue chips (460 nm,
250 mW, 350 mA, APT Electronics Ltd., China) were used to fabricate white light-emitting
diodes (WLEDs). The phosphors were mixed with silicone resin (Dow Corning OE-6630 A and
B) thoroughly. The obtained phosphor–silicone mixture was used to coat the surface of the LED
chips. The photoelectric properties of the fabricated devices were measured by an integrating
sphere spectroradiometer (PMS-80, Everfine Photo-EINFO Co. Ltd., China). The LEDs were
operated at voltage 3.0 V and current 200 mA.
2. Evaluating the moisture resistance of WLED using K2SiF6:Mn4+red phosphors
The WLEDs, including the commercial -SiAlON:Eu2+ green phosphor, commercial
K2SiF6:Mn4+ (Sharp Chemical, Japan) red phosphor or the prepared K2SiF6:Mn4+ red phosphors
and blue chips (455 nm, EPISTAR Co., Ltd., Taiwan) were prepared on a devices board (Figure
S1). The WLED fabrication was carried out following the same process used in the package test.
The waterproof properties of the fabricated devices were detected by measuring their quantum
yield at high humidity atmosphere (85%) and high temperature (85 C) using a heating system
(KSON Instrument Technology, Taiwan) and an integrating sphere spectroradiometer (LB X–Y
TABLE-L, WEI MIN Industrial Co., Ltd., China). The LEDs were operated at 2.0 V with a
current of 120 mA for 2,016 h.
3. Characterization of materials
The obtained phosphor structure was examined via X-ray powder diffraction (XRD;
D2PHASER:Cu-K radiation, Bruker AXS, Germany). A field-emission scanning electron
microscopy with energy dispersive X-ray spectroscopy scanning electron microscope (FESEMEDS, JEOL JSM-6700F, Japan) was used to examine the morphology and elemental composition
of the materials. The thickness of the coating layers was observed through high resolution
transmission electron microscopy (HRTEM, JEOL-2100F, Japan). Surface analysis of the
samples was performed using X-ray photoelectron spectroscopy (XPS, Al-K radiation, PHI
Quantera, USA). A FluoroMax-3 spectrophotometer (HORIBA, Japan) equipped with a 150 W
Xe lamp was used to measure the RT excitation and emission spectra. For the temperaturedependent experiments at 303–573 K, the samples were placed in a small platinum hold, and
temperature was controlled by a heating THMS-600 device (Linkam Scientific Instruments Ltd.,
UK). Light was radiated by a Hamamatsu R928 photo-multiplier tube. The internal and external
quantum efficiencies of the phosphors were detected through the Absolute PL quantum yield
spectrometer (QY C11347, Hamamatsu, Japan). Oven (Model No. GTH-080ST-SP, Giant Force
Instrument Enterprise Co., Taiwan) with humidity (60-90%) and temperature (30-100 C)
controller was used to test moisture resistance of the phosphors.
Figure S1. (a) The WLED board, including a blue-LED chip, commercial -SiAlON:Eu2+ green
phosphor, and K2SiF6:Mn4+ red phosphor; (b) the HH&HT system controlling the current
application (KSON Instrument Technology, Taiwan); and (c) the integrating sphere
spectroradiometer (LB X–Y TABLE-L, WEI MIN Industrial Co., Ltd., China).
Figure S2. FESEM images of KSFM-MOPAl coated with various OP concentrations (a, b) 0.00
M, (c, d) 0.01 M, (e, f) 0.05 M, and (g, h) 0.10 M.
Figure S3. (a) PLE and (b) PL spectra KSFM-MOPAl with various OP concentrations: () 0.00
M, () 0.01 M, (δ) 0.05 M, and () 0.10 M.
Figure S4. Images of (a) KSFM and (b) KSFM-MOPAl in deionized water at various times.
Figure S5. Emission spectra of (a) KSFM, (b) KSFM-MOPZn, (c) KSFM-MOPAl, and (d)
KSFM-MOPTi in deionized water at various times.
Figure S6. Integrated luminescence intensities (IPL at t/IPL at t = 0), as a function of time, of (a)
KSFM, (b) KSFM-MOPZn, (c) KSFM-MOPAl, and (d) KSFM-MOPTi in deionized water.
Figure S7. Temperature-dependent emission spectra of KSFM-MOPAl with various OP
concentrations, as follows: (a) 0.00 M, (b) 0.01 M, (c) 0.05 M, and (d) 0.10 M.
Figure S8. Chromaticity coordinate of the WLEDs fabricated by combining blue-LED chip with
(a) YAG:Ce3+ and prepared KSFM, (b) YAG:Ce3+ and KSFM-MOPAl, and (c) -SiAlON:Eu2+
and KSFM-MOPAl in the Commission Internationale de IʹÉclairage (CIE) 1931 color spaces.
Figure S9. Luminescence spectra of WLEDs using blue-LED chip with (a) YAG:Ce3+ yellowphosphor and KSFM red phosphor, (b) YAG:Ce3+ yellow-phosphor and KSFM-MOPAl red
phosphor, and (c) -SiAlON:Eu2+ green phosphor and KSFM-MOPAl red phosphor. Inserted
pictures show bright warm white light emitted from the fabricated WLEDs.
Figure S10. Relative quantum efficiency of WLEDs using commercial -SiAlON:Eu2+ green
phosphor and (a) commercial KSFM, (b) prepared KSFM, and (c) KSFM-MOPAl red phosphor
for 2,016 h in a high humidity (85%) and at high temperature (85 C) environment at a 120 mA
application.
Figure S11. Curves that estimate time at 50% original intensity of the WLEDs using SiAlON:Eu2+ and (a) commercial KSFM (3,660 h), (b) prepared KSFM (4,627 h), and (c)
KSFM-MOPAl (8,159 h). The linear regression equations used were y = 0.962805e‒0.000179x, y =
1.010215e‒0.000152x, and y = 1.000346e‒0.000085x for WLED/cKSFM, WLED/pKSFM, and
WLED/coatedKSFM, respectively, where y is the relative luminous ratio (%) and x is the aging
time in an HH&HT atmosphere.
Table S1. Quantum efficiency of the prepared KSFM and KSFM-MOPAl with various OP
concentrations measured in a high humidity (85%) and high temperature (85 C) atmosphere for
30 days.
KSFM
Day
IQE
RIQE (%)
EQE
REQE (%)
0
0.815
100.0
0.556
100.0
1
0.676
82.9
0.494
88.8
2
0.627
76.9
0.466
83.8
3
0.640
78.5
0.472
84.9
4
0.615
75.5
0.465
83.7
5
0.592
72.6
0.459
82.6
10
0.600
73.6
0.464
83.5
20
0.550
67.5
0.445
79.7
30
0.464
56.9
0.358
64.4
KSFM-MOPAl (0.01 M)
Day
IQE
RIQE (%)
EQE
REQE (%)
0
0.790
100.0
0.549
100.0
1
0.772
97.7
0.534
97.3
2
0.751
95.0
0.519
94.5
3
0.727
92.0
0.515
93.8
4
0.694
87.8
0.495
90.2
5
0.681
86.2
0.490
89.3
10
0.675
85.4
0.488
88.9
20
0.648
82.0
0.472
86.0
30
0.609
77.1
0.437
79.6
KSFM-MOPAl (0.05 M)
Day
IQE
RIQE (%)
EQE
REQE (%)
0
0.735
100.0
0.517
100.0
1
0.724
98.5
0.507
98.1
2
0.717
97.6
0.497
96.1
3
0.698
95.0
0.497
96.1
4
0.696
94.5
0.492
95.2
5
0.683
92.9
0.486
94.0
10
0.677
92.1
0.476
92.1
20
0.646
87.9
0.472
91.3
30
0.624
84.9
0.451
87.2
KSFM-MOPAl (0.10 M)
Day
IQE
RIQE (%)
EQE
REQE (%)
0
0.729
100.0
0.506
100.0
1
0.709
97.3
0.497
98.2
2
0.691
94.8
0.471
93.1
3
0.661
90.7
0.469
92.7
4
0.652
89.4
0.466
92.1
5
0.650
89.2
0.461
91.1
10
0.643
88.2
0.461
91.1
20
0.613
84.1
0.450
88.9
30
0.611
83.8
0.442
87.4