1. Department School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China
2. Key Laboratory of Semiconductor Materials Science and Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China
3. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
4. Department of Physics, Hebei Normal University of Science & Technology, Qinhuangdao 066004, China