The ability to tune the emission color of materials by external stimuli like electric field, pressure, temperature, etc., offers avenues to design light-based sensors and devices. We report here a new strategy which enables large temperature tuning of the emission color of a lanthanide phosphor by combining Raman and photoluminescence (PL) signals. The phenomenon and the associated mechanism, demonstrated on Eu, Er doped BaTiO₃, shows the emission color to change from orange to green when cooled down to 10 K. The large color tuning is a consequence of synergy of the two processes: (i) significant enhancement of the Raman signal due to gradual structural ordering in the rhombohedral ferroelectric phase of the host BaTiO₃ and (ii) anomalous low temperature quenching of the PL emission of the doped Eu³⁺ by trap states. We show that this contrasting temperature effect on the PL and the Raman signals can be used as a powerful strategy to design phosphor materials for high performance optical thermometry.

中文翻译：

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通过同时使用拉曼信号和光致发光信号对磷光体的发射颜色进行大范围的温度调节

通过外部刺激（例如电场，压力，温度等）调整材料的发射颜色的能力为设计基于光的传感器和设备提供了途径。我们在这里报告了一种新的策略，该策略可以通过组合拉曼信号和光致发光（PL）信号对镧系元素磷光体的发射颜色进行大的温度调节。在Eu，Er掺杂的BaTiO ₃上证明的现象和相关机理表明，当冷却至10 K时，发射颜色从橙色变为绿色。大的颜色调整是两个过程协同作用的结果：（i）由于主体BaTiO ₃的菱面体铁电相中的逐渐结构有序性，拉曼信号的显着增强（ii）通过陷阱态对掺杂的Eu ³⁺的PL发射进行异常低温淬灭。我们表明，对PL和拉曼信号的这种相反的温度影响可以用作设计用于高性能光学测温的荧光粉材料的有力策略。