Li Pengfei, Peng Mingying, Yin Xuewen, Ma Zhijun, Dong Guoping, Zhang Qinyuan, Qiu Jianrong
State Key Laboratory of Luminescent Materials and Devices, Institute of Optical Communication Materials, School of Materials Science and Technology, South China University of Technology, Guangzhou 510640, China.
Opt Express. 2013 Aug 12;21(16):18943-8. doi: 10.1364/OE.21.018943.
Thermal luminescence quenching behavior of a phosphor is essential for application in phosphor converted white light emitting diodes (pc-WLEDs) because the phosphor layer can be heated up to 473K in a working high power WLEDs. Here, we have confirmed indeed a red luminescence of Mn(4+) substituting for calcium sites rather than tetrahedral aluminum sites in CaAl(4)O(7):Mn which can be synthesized in pure phase even with boron acid as flux, and examined the low and high temperature luminescent properties in the range of 10 to 500K. We have revealed as well as thermal quenching mechanism that distorted octahedral Mn(4+) sites suffer severe thermal quenching. This work, thus, hints a strategy to find a new Mn(4+) phosphor with better resistance to thermal impact in the future.
磷光体的热发光猝灭行为对于应用于磷光体转换白光发光二极管（pc-WLED）至关重要，因为在工作的高功率WLED中，磷光体层可被加热至473K。在此，我们确实证实了在CaAl(4)O(7):Mn中，取代钙位点而非四面体铝位点的Mn(4+)发出红色发光，即使以硼酸为助熔剂也能合成纯相，并研究了10至500K范围内的低温和高温发光特性。我们还揭示了畸变八面体Mn(4+)位点遭受严重热猝灭的热猝灭机制。因此，这项工作为未来寻找一种对热冲击具有更好抗性的新型Mn(4+)磷光体提示了一种策略。
