Abstract 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.

中文翻译：

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用于 UV-LED 的单相 SrY2O4:Bi3+,Sm3+ 荧光粉的能量转移和高热稳定性

摘要 热猝灭是紫外转换白光发光二极管 (UV Converted WLED) 在高驱动电流下工作时面临的最关键挑战之一，其中荧光粉会因温度升高而遭受非辐射跃迁导致的发光损失。 . 在此，采用高温固相策略成功制备了具有异常热猝灭性能的新型单相Bi3+、Sm3+掺杂的SrY2O4（SYO）荧光粉。采用 X 射线衍射、发光行为、寿命和温度相关的发射特性来研究获得的粉末材料。在紫外光照射下，基于通过偶极-偶极机制从 Bi3+ 到 Sm3+ 的能量转移 (ET)，实现了从蓝色到红色的可调发射。显着地，所获得的磷光体即使在高达 573 K (300 °C) 的温度下也不会表现出热猝灭。它们即使在高温下也表现出微小的色度偏移，表明其具有出色的颜色稳定性。这些现象可以被 ET 从缺陷能级解释为 Bi3+ 激发态，这是通过热释光测量确定的。这些结果表明 SYO:Bi3+,Sm3+ 在 UV 转换 WLED 中的潜在应用。