1. Anhui Key Laboratory of Low Temperature Co-fired Materials, Department of Physics and Department of Chemistry, Huainan Normal University, Huainan 232038, China
2. School of Physics and Electromechanical EngineeringLongyan University, Longyan 364000, China
3. Key Laboratory of Optoelectronic Materials Chemistry and Physics, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China