1. State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics, Sun Yat-Sen University, Guangzhou 510275, China
2. State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou 510275, China
3. Research and Development Center for Solid-state Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
4. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100190, China
5. College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China