Abstract In this work, YVO4: Eu3+ phosphors with and without Ba2+ doping (having the formula of Y1-x-y (EuxBay)VO4) were prepared by the high-temperature solid-state reaction method, and their photoluminescence and relevant physical mechanism were studied. A large enhancement in the photoluminescence of the YVO4: Eu3+ phosphors by Ba2+ doping has been observed. When the Ba2+ doping concentration is at 3 at%, the YVO4: Eu3+ phosphors have the strongest photoluminescence. It has been found that the Ba2+ doping extends the luminescence decay lifetimes of YVO4: Eu3+. In addition, the Ba2+ doping also makes the charge transfer state absorption band of VO43− blue shifted and widens the 5D0→7F2 emission of Eu3+. The underlying mechanism for these results has been investigated using the first principles calculations. It has been shown that the Ba2+ doping increases the bandgap value of YVO4 and causes the energy level of the Eu-d orbit to split, and the individual atomic orbitals move toward higher energy after Ba2+ doping. A higher energy transfer efficiency from VO43− to Eu3+ has been predicted by the first principles calculations. The theoretical calculation results explain the photoluminescence enhancement of YVO4: Eu3+ by Ba2+ doping, and the mechanism has been revealed.

中文翻译：

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Ba2+掺杂对YVO4:Eu3+荧光粉光致发光的影响和第一性原理计算

摘要 本工作采用高温固相反应法制备了掺杂和不掺杂Ba2+的YVO4:Eu3+荧光粉（分子式为Y1-xy (EuxBay)VO4），并对其光致发光及相关物理机理进行了研究。已经观察到 YVO4:Eu3+ 磷光体通过 Ba2+ 掺杂大大增强了光致发光。当 Ba2+ 掺杂浓度为 3 at% 时，YVO4:Eu3+ 荧光粉具有最强的光致发光。已经发现Ba2+掺杂延长了YVO4:Eu3+的发光衰减寿命。此外，Ba2+的掺杂还使VO43−的电荷转移态吸收带发生蓝移，扩大了Eu3+的5D0→7F2发射。已经使用第一性原理计算研究了这些结果的潜在机制。研究表明，Ba2+ 掺杂增加了 YVO4 的带隙值并导致 Eu-d 轨道的能级分裂，并且在 Ba2+ 掺杂后单个原子轨道向更高的能量移动。第一性原理计算预测了从 VO43− 到 Eu3+ 的更高能量转移效率。理论计算结果解释了Ba2+掺杂对YVO4:Eu3+的光致发光增强作用，并揭示了机理。