期刊
JOURNAL OF PHYSICAL CHEMISTRY C
卷 119, 期 44, 页码 25003-25008出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.jpcc.5b08828
关键词
-
资金
- Project of Strategic Young Researcher Overseas Visits Program for Accelerating Brain Circulation (International Network-hub for Future Earth: Research for Global Sustainability)
Y3Al5O12(YAG):Ce3+ is the most widely applied phosphor in white LEDs (w-LEDs) because of strong blue absorption and efficient yellow luminescence combined with a high stability and thermal quenching temperature, required for the extreme operating conditions in high-power w-LEDs. The high luminescence quenching temperature (similar to 600 K) has been well established, but surprisingly, the mechanism for temperature quenching has not been elucidated yet. In this report we investigate the possibility of thermal ionization as a cause of this quenching process by measuring thermoluminescence (TL) excitation spectra at various temperatures. In the TL excitation (TLE) spectrum at room temperature there is no Ce3+:5d(1) band (the lowest excited 5d level). However, in the TLE spectrum at 573 K, which corresponds to the onset temperature of luminescence quenching, a TLE band due to the Ce3+:5d(1) excitation was observed at around 450 nm. On the basis of our observations we conclude that the luminescence quenching of YAG:Ce3+ at high temperatures is caused by the thermal ionization and not by the thermally activated cross over to the 4f ground state. The conclusion is confirmed by analysis of the positions of the Sd states of Ce3+ relative to the conduction band in the energy band diagram of YAG:Ce3+.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据