High temperature degradation mechanism of a red phosphor, CaAlSiN3:Eu for solid-state lighting
| Autor: | Masatsugu Oishi, Kazunobu Kojima, Shigefusa F. Chichibu, Aiko Takatori, Yoichiro Kai, Takashi Yamamoto, Tomoyuki Ueki, Shohei Shiomi |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Photoluminescence General Physics and Astronomy Mineralogy Phosphor 02 engineering and technology Crystal structure 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences 0104 chemical sciences Ion law.invention Solid-state lighting law Thermal Degradation (geology) 0210 nano-technology Luminescence |
| Zdroj: | Journal of Applied Physics. 122:113104 |
| ISSN: | 1089-7550 0021-8979 |
| Popis: | Thermal properties of a red phosphor CaAlSiN3:Eu (CASN) at elevated temperatures were evaluated. A heat treatment at 800 °C degraded the photoluminescence property of CASN and caused irreversible changes in both the excitation and emission intensities. The heat treatment in air simultaneously decreased the N elements and increased the O elements. Consequently, the Eu2+ luminescence center was oxidized and CASN lost its photoluminescence property. Although the crystal structure of CASN host was stable even after the heat treatments, the local structure change around the Eu2+ ions is the origin of the thermal degradation of CASN. We found that the heat treatment in N2 atmosphere suppresses the thermal degradation. This is due to the suppression of N evolutions and the incorporation of O elements, which sustains the optically active Eu2+ state. |
| Databáze: | OpenAIRE |
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