Controlling disorder in host lattice by hetero-valence ion doping to manipulate luminescence in spinel solid solution phosphors

作     者：Qinqin Ma Jie Wang Wei Zheng Qian Wang Zhiheng Li Hengjiang Cong Huijun Liu Xueyuan Chen Quan Yuan 

作者机构：Key Laboratory of Analytical Chemistry for Biology and Medicine(Ministry of Education) College of Chemistry and Molecular SciencesWuhan University CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Key Laboratory of Nanomaterials Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences Key Laboratory of Artificial Micro-and Nano-Structures of Ministry of Education and School of Physics and Technology Wuhan University 

出 版 物：《Science China Chemistry》 (中国科学（化学英文版）)

年 卷 期：2018年第61卷第12期

页      面：1624-1629页

核心收录：

学科分类：07[理学] 0703[理学-化学] 

基　　金：supported by the National Key R&D Program of China (2017YFA0208000) the National Natural Science Foundation of China (21675120, 21325104) the CAS/SAFEA International Partnership Program for Creative Research Teams 

主　　题：persistent luminescence nanoparticle defect doping 

摘      要：Phosphor materials have been rapidly developed in the past decades. Developing phosphors with desired properties including strong luminescence intensity and long lifetime has attracted widespread attention. Herein, we show that hetero-valence ion doping can serve as a potent strategy to manipulate luminescence in persistent phosphors by controlling disorder in the host lattice. Specifically, spinel phosphor Zn(Ga_(1-x)Zn_x)(Ga_(1-x)Ge_x)O_4:Cr is developed by doping ZnGa_2O_4:Cr with tetravalent Ge^(^(4+)).Compared to the original ZnGa_2O_4:Cr, the doped Zn(Ga_(1-x)Zn_x)(Ga_(1-x)Ge_x)O_4:Cr possesses significantly enhanced persistent luminescence intensity and prolonged decay time. Rietveld refinements show that Ge^(4+)enters into octahedral sites to substitute Ga^(3+), which leads to the co-substitution of Ga^(3+) by Zn^(2+) for charge compensation. The hetero-valence substitution of Ga^(3+) by Ge^(4+)and Zn^(2+) enriches the charged defects in Zn(Ga_(1-x)Zn_x)(Ga_(1-x)Ge_x)O_4:Cr, making it possible to trap large amounts of charge carriers within the defects during excitation. Electron paramagnetic resonance measurement further confirms that the amount of Cr^(3+) neighboring charged defects increases with Ge^(4+)doping. Thus charge carriers released from defects can readily combine with the neighboring Cr^(3+) to produce bright persistent luminescence after excitation ceases. The hetero-valence ion doping strategy can further be employed to develop many other phosphors and contributes to lighting, photocatalysis and bioimaging.