1. Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, China
2. Key Laboratory of New Energy and Rare Earth Resource Utilization of State Ethnic Affairs Commission, School of Physics and Materials Engineering, Dalian Minzu University, Dalian 116600, China
3. State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 130012 Changchun, China
4. Department of Materials Science, Fudan University, Shanghai 200433, China