[19p-G204-1~8] 13.8 Optical properties and light-emitting devices

[19p-G204-7] Characterization of high temperature degradation mechanism of a red phosphor, CaAlSiN₃:Eu

〇Masatsugu Oishi^1,2, Shohei Shiomi³, Takashi Yamamoto¹, Tomoyuki Ueki¹, Yoichiro Kai², Shigefusa Chichibu⁴, Aiko Takatori², Kazunobu Kojima^4,2 (1.Tokushima Univ., 2.Yawarakana Hikari Project, 3.Kyoto Municipal Institute of Industrial Technology and Culture, 4.IMRAM, Tohoku Univ.)

Keywords:a red nitride phosphor, High temperature property

We have found the thermal degradation mechanism of a red phosphor CaAlSiN3:Eu (CASN) at the elevated temperatures by directly evaluating the electronic structure of the elimination center of Eu2+ ions. The evolution of N2 at the elevated temperature caused EuN4 tetrahedral symmetry distortion and it caused the irreversible changes of the electronic structure of Eu2+ ions. Further distortion resulted in oxidation to Eu3+ states and the photoluminescence property was lost.