First‐principles and crystal‐field calculations of the electronic and optical properties of two novel red phosphors Rb2HfF6:Mn4+ and Cs2HfF6:Mn4+
First‐principles and crystal‐field calculations of the electronic and optical properties of two novel red phosphors Rb2HfF6:Mn4+ and Cs2HfF6:Mn4+
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DOI：
10.1111/jace.15406
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发表时间：
2018-06
影响因子：
3.9
通讯作者：
Dong-Xu Liu;Chonggeng Ma;Pei-wen Hu;Zuo Li;Ya Tian;P. Su;M. Brik;A. Srivastava;S. Tanabe
中科院分区：
文献类型：
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作者：
Dong-Xu Liu;Chonggeng Ma;Pei-wen Hu;Zuo Li;Ya Tian;P. Su;M. Brik;A. Srivastava;S. Tanabe
利用第一性原理和晶体场理论方法对Rb2HfF6:Mn4+和Cs2HfF6:Mn4+两种红色荧光粉的电子、结构和光学性质进行了评价。计算得到的Mn4+轨道三重态的三角分裂与实验激发谱完全吻合。从理论上研究了混合化合物rbcshff6的结构和电子性能。在混合化合物中，Hf位点周围的反转中心对称性被去除。这种对称性的降低可能导致Mn4+2E→4a20零声子线（ZPL）强度的增加，而该强度在2端成员中非常弱。这一发现可能对增加荧光粉的光度有意义。我们相信，这种通过制备固化剂来降低局部位置对称性的机制也可以用于其他系统，以获得ZPL强度，并可能最小化热损失，最终导致改进的荧光粉材料。
The electronic, structural, and optical properties of 2 red phosphors, Rb2HfF6:Mn4+and Cs2HfF6:Mn4+, are evaluated using the first‐principles and crystal field theory methods. The calculated trigonal splitting of the Mn4+orbital triplets perfectly matches the experimental excitation spectra. The structural and electronic properties of the mixed compound RbCsHfF6are also studied theoretically. In the mixed compound, the inversion center symmetry around the Hf site is removed. This symmetry lowering may result in an increase in the Mn4+2E→4A2zero phonon line (ZPL) intensity, which is very weak in the 2 end members. This finding may be of interest for increasing the phosphor luminosity. It is believed that such a mechanism of local site symmetry lowering by preparing solid solutions may be used for other systems as well, to gain ZPL intensity and perhaps to minimize thermal losses, eventually leading to improved phosphor materials.