Yu Chunfeng, Chen Baojiu, Zhang Xizhen, Li Xiangping, Zhang Jinsu, Xu Sai, Yu Hongquan, Sun Jiashi, Cao Yongze, Xia Haiping
School of Science, Dalian Maritime University, Dalian, Liaoning 116026, P. R. China.
Key Laboratory of Photo-electronic Materials, Ningbo University, Ningbo, Zhejiang 315211, P. R. China.
Phys Chem Chem Phys. 2020 Apr 15;22(15):7844-7852. doi: 10.1039/c9cp06755h.
The optical transition properties of trivalent rare earth (RE3+) doped luminescent materials have received extensive attention. The Judd-Ofelt theory is an effective tool for exploring the optical transition properties for the 4f-4f transitions of lanthanides. The aim of this work is to discover the effect of Er3+ concentration and different Ln3+ ions on the Judd-Ofelt parameters in LnOCl:Er3+ (Ln = Y, La, Gd) phosphors. Oxychloride LnOCl:Er3+ (Ln = Y, La, Gd) phosphors were produced via a single displacement reaction technique. The Judd-Ofelt calculation procedure for RE3+ doped powders was modified and then adopted to obtain the Judd-Ofelt parameters of Er3+ in the studied phosphors. Meanwhile, a new route for examining the Judd-Ofelt calculation quality was proposed and used. It was found that the Er3+ doping concentration slightly affects the optical transition properties of Er3+ in YOCl and LaOCl, but greatly affects the optical transition properties in GdOCl. Moreover, it was also found that the optical transition properties of Er3+ depend also on Ln3+ (Ln = Y, La, Gd) though the crystal structure of these compounds is similar. The Judd-Ofelt parameters of Er3+ are the smallest in LaOCl:Er3+, medium in YOCl:Er3+, but the biggest in GdOCl:Er3+ when the doping concentration is the same.
三价稀土（RE3+）掺杂发光材料的光学跃迁特性受到了广泛关注。贾德-奥费尔特理论是探索镧系元素4f-4f跃迁光学跃迁特性的有效工具。这项工作的目的是研究Er3+浓度和不同Ln3+离子对LnOCl:Er3+（Ln = Y、La、Gd）荧光粉中贾德-奥费尔特参数的影响。通过单置换反应技术制备了氯氧化物LnOCl:Er3+（Ln = Y、La、Gd）荧光粉。对RE3+掺杂粉末的贾德-奥费尔特计算程序进行了修改，然后用于获得所研究荧光粉中Er3+的贾德-奥费尔特参数。同时，提出并采用了一种检验贾德-奥费尔特计算质量的新方法。结果发现，Er3+掺杂浓度对YOCl和LaOCl中Er3+的光学跃迁特性影响较小，但对GdOCl中的光学跃迁特性影响较大。此外，还发现尽管这些化合物的晶体结构相似，但Er3+的光学跃迁特性也取决于Ln3+（Ln = Y、La、Gd）。当掺杂浓度相同时，LaOCl:Er3+中Er3+的贾德-奥费尔特参数最小，YOCl:Er3+中次之，而GdOCl:Er3+中最大。
