1. Laboratory of Information Functional Materials and Devices, School of Science, Beijing University of Posts and Telecommunications, Beijing 100876, People's Republic of China
2. State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, People's Republic of China
3. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
4. The Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, People's Republic of China
5. College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331, People's Republic of China