Energy transfer and highly thermal stability in single-phase SrY2O4:Bi3+, Sm3+ phosphors for UV-LEDs
Energy transfer and highly thermal stability in single-phase SrY2O4:Bi3+, Sm3+ phosphors for UV-LEDs
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用于 UV-LED 的单相 SrY2O4:Bi3、Sm3 荧光粉的能量传输和高热稳定性
DOI：
10.1016/j.jlumin.2020.117606
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发表时间：
2020
影响因子：
3.6
通讯作者：
Guo Hai
中科院分区：
文献类型：
--
作者：
Wei Rongfei;Yang Lupeng;Zhang Xing;Tian Xiangling;Peng Xiusha;Hu Fangfang;Guo Hai
热猝灭是紫外转换白色发光二极管（UV转换WLED）在高驱动电流下工作时面临的最关键的挑战之一，其中磷光体经受随温度增加的非辐射跃迁导致的发光损失。本文采用高温固相法成功制备了具有反常热猝灭特性的新型单相Bi 3+，Sm 3+掺杂SrY 2 O 4（SYO）荧光粉。采用X射线衍射、发光行为、寿命和随温度变化的发光性能对所得粉末材料进行了研究。在紫外光照射下，通过偶极-偶极机制实现了Bi ~（3+）向Sm ~（3+）的能量转移，实现了从蓝色到红色的可调谐发光。值得注意的是，所获得的磷光体甚至在高达573 K（300 °C）时也不显示热猝灭。而且，即使在高温下，它们也表现出微小的色度偏移，这表明它们具有优异的颜色稳定性。这些现象可以解释的ET从缺陷能级到Bi 3+激发态，这是确定的热释光测量。这些结果表明SYO：Bi ~（3+），Sm ~（3+）在紫外转换WLED中具有潜在的应用价值。
Thermal quenching is one of the most key challenges of ultraviolet converted white light-emitting diodes (UV converted WLEDs) when they operate at high driving current, in which the phosphors are subjected to the luminescence losses resulting from non-radiative transitions with augmenting temperature. Herein, novel single-phased Bi3+,Sm3+-doped SrY2O4(SYO) phosphors with abnormal thermal quenching property were successfully prepared applying a high-temperature solid-state strategy. X-ray diffraction, luminescent behaviors, lifetimes and temperature-dependent emission properties were employed to study the obtained powder materials. Under UV light irradiation, tunable emission from blue to red based on the energy transfer (ET) from Bi3+to Sm3+via a dipole-dipole mechanism is realized. Significantly, the obtained phosphors do not display thermal quenching even up to 573 K (300 °C). And they exhibit tiny chromaticity shift even at high temperature, indicative of excellent color stability. These phenomena may be interpreted by the ET from defect levels to Bi3+excited states, which was identified by thermoluminescence measurements. These results indicate potential applications of SYO:Bi3+,Sm3+in UV converted WLEDs.