Effects of Fluoride Dopants in the Starting Materials for BaAl2S4:Eu Thin-Film Phosphors
BaF 2 and AlF 3 were used for the preparation of BaAl 2 S 4 :Eu thin-film phosphors. The blue emission with a peak at 470 nm was obtained particularly because the process temperature was not sufficient for obtaining a peak at 470 nm in the case of a conventional technique. The intensity of the blue...
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| Published in | Jpn J Appl Phys Vol. 49; no. 1; pp. 012401 - 012401-5 |
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| Main Authors | , , , |
| Format | Journal Article |
| Language | English |
| Published |
The Japan Society of Applied Physics
01.01.2010
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| Online Access | Get full text |
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| Summary: | BaF 2 and AlF 3 were used for the preparation of BaAl 2 S 4 :Eu thin-film phosphors. The blue emission with a peak at 470 nm was obtained particularly because the process temperature was not sufficient for obtaining a peak at 470 nm in the case of a conventional technique. The intensity of the blue emission from BaAl 2 S 4 :Eu phosphors prepared using fluoride compounds was higher than that of phosphors prepared without fluoride compounds, and the appropriate annealing temperature decreased during the preparation process. It is considered that BaF 2 and AlF 3 enhanced the reaction of starting materials and accelerated the crystallization of BaAl 2 S 4 . The crystallinity and mean crystal particle size of BaAl 2 S 4 :Eu phosphors prepared using fluoride compounds were improved. This is due to the fluoride compounds effectively acting as flux materials. |
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| Bibliography: | Photoluminescence spectrum of BaAl 2 S 4 :Eu phosphors prepared using AlF 3 (10 mol %). The emission peak wavelength of BaAl 2 S 4 :Eu powder phosphors as a function of fluoride compound concentration in the source material is also shown in the inset. Relative photoluminescence intensity of BaAl 2 S 4 :Eu phosphors prepared using fluoride compounds as a function of fluoride compound concentration. X-ray diffraction patterns of BaAl 2 S 4 :Eu phosphors synthesized with AlF 3 . The concentrations of AlF 3 are (a) 0, (b) 1, (c) 10, and (d) 20 mol %. (e) Diffraction data of cubic BaAl 2 S 4 in the JCPDS card. The full width at half maximum (FWHM) of the diffraction signal from the (311) lattice plane is also shown. Scanning electron microscopy images of BaAl 2 S 4 :Eu phosphors synthesized (a) without fluoride compounds, (b) with BaF 2 , and (c) with AlF 3 . The concentrations of BaF 2 and AlF 3 are 5 and 10 mol %, respectively. Relative photoluminescence intensity of BaAl 2 S 4 :Eu phosphors synthesized using fluoride compounds as a function of synthesizing temperature. The concentrations of BaF 2 and AlF 3 are 5 and 10 mol %, respectively. The PL intensity of BaAl 2 S 4 :Eu phosphors synthesized without fluoride materials is also shown. Photoluminescence spectrum of BaAl 2 S 4 :Eu thin films prepared using AlF 3 (10 mol %). The annealing temperature is 760 \mbox{ \circ C}. The peak wavelength of BaAl 2 S 4 :Eu thin film phosphors as a function of (a) fluoride compound concentration in an evaporation material (annealing temperature: 760 \mbox{ \circ C}) and (b) annealing temperature of BaAl 2 S 4 :Eu thin films prepared with AlF 3 (10 mol %). Relative photoluminescence intensity of BaAl 2 S 4 :Eu thin films prepared using BaF 2 as a function of BaF 2 concentration. The concentration is the molar ratio of BaF 2 to BaAl 2 S 4 . The thin films were annealed at 680, 720, 760, and 800 \mbox{ \circ C}. Relative photoluminescence intensity of BaAl 2 S 4 :Eu thin films prepared using AlF 3 as a function of AlF 3 concentration. The concentration is the molar ratio of AlF 3 to BaAl 2 S 4 . The thin films were annealed at 680, 720, 760, and 800 \mbox{ \circ C}. X-ray diffraction patterns of BaAl 2 S 4 :Eu thin films prepared (a) without fluoride compounds, (b) with BaF 2 , and (c) with AlF 3 . The concentrations of BaF 2 and AlF 3 are 5 and 10 mol %, respectively. The annealing temperature is 760 \mbox{ \circ C}. |
| ISSN: | 0021-4922 1347-4065 |
| DOI: | 10.1143/JJAP.49.012401 |