Thermal Quenching Mechanism of CaAlSiN3:Eu2+ Red Phosphor
Thermal Quenching Mechanism of CaAlSiN3:Eu2+ Red Phosphor
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DOI：
10.1246/bcsj.20170307
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发表时间：
2017-11
影响因子：
4
通讯作者：
J. Ueda;S. Tanabe;Kohsei Takahashi;T. Takeda;N. Hirosaki
中科院分区：
文献类型：
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作者：
J. Ueda;S. Tanabe;Kohsei Takahashi;T. Takeda;N. Hirosaki
CaAlSiN 3：Eu 2+由于具有很强的蓝光吸收和很高的热猝灭温度，在白色LED（w-LED）中得到了广泛的应用。对热猝灭的良好稳定性已经被很好地建立，但在高温下的发光猝灭的机制尚未阐明。在这份报告中，我们调查的可能性，热电离猝灭的热释光（TL）和持续发光技术。在100 K下紫外充电的热释光发光曲线中，在160和390 K附近观察到两个宽的热释光发光带。在300 K下550 nm充电没有观察到较高的TL辉光带，但在400 K以上的550 nm充电时观察到较高的TL辉光带，这对应于发光猝灭的起始温度。由于550 nm的光激发了Eu 2+的最低5d能级，我们认为CaAlSiN 3：Eu 2+在高温下的发光猝灭是由热电离引起的。
CaAlSiN3:Eu2+ is a widely applied phosphor in white LEDs (w-LEDs) because of strong blue absorption and efficient red luminescence with high thermal quenching temperature. The good stability against thermal quenching has been well established, but the mechanism for the luminescence quenching at high temperatures has not been elucidated yet. In this report, we investigate the possibility of thermal ionization quenching by thermoluminescence (TL) and persistent luminescence techniques. In the TL glow curve by UV charging at 100 K, two broad TL glow bands were observed around 160 and 390 K. The higher TL glow band was not observed by 550 nm charging at 300 K, but it was observed by 550 nm charging at above 400 K which corresponds to the onset temperature of luminescence quenching. Because the 550 nm light excites the lowest 5d level of Eu2+, we conclude that the luminescence quenching of CaAlSiN3:Eu2+ at high temperatures is caused by the thermal ionization.