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A new CaF2-YAG:Ce composite phosphor ceramic for high-power and high-color-rendering WLEDs.
- Source :
- Journal of Materials Chemistry C; 7/28/2019, Vol. 7 Issue 28, p8569-8574, 6p
- Publication Year :
- 2019
-
Abstract
- Thermally robust and optically transparent phosphor ceramics are now attracting great attention as promising luminescent materials for high-power white light-emitting diodes (WLEDs). Here, we report a new CaF<subscript>2</subscript>-YAG:Ce phosphor ceramic in which the yellow-emitting YAG:Ce particles are embedded in a non-luminescent CaF<subscript>2</subscript> ceramic matrix. The composite phosphor ceramic was fabricated at a very low sintering temperature of 700 °C by using a simple hot-pressing method. No detectable interfacial reaction occurs between the YAG:Ce particle and the CaF<subscript>2</subscript> matrix. Owing to the excellent optical properties and high thermal conductivity of CaF<subscript>2</subscript>, the prepared CaF<subscript>2</subscript>-YAG:Ce phosphor ceramic shows a high quantum efficiency (IQE = 83.2%), and a low thermal quenching (only 9% loss in luminescence at 150 °C). WLEDs, fabricated by combining the CaF<subscript>2</subscript>-YAG:Ce phosphor ceramic with a 460 nm blue chip of 2 W, exhibited bright white light with a luminous flux of 359.7 lm, a color temperature of 4021–7941 K and a color rendering index of 70.1–82.7. The composite phosphor ceramic showed a better performance than the traditional single-phase YAG:Ce ceramic, enabling it to be used in high-power WLEDs. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 20507526
- Volume :
- 7
- Issue :
- 28
- Database :
- Complementary Index
- Journal :
- Journal of Materials Chemistry C
- Publication Type :
- Academic Journal
- Accession number :
- 137576163
- Full Text :
- https://doi.org/10.1039/c9tc02407g