1. State Key Laboratory of Crystal Materials; Shandong University; Jinan 250100 P. R. China
2. State Key Laboratory of Integrated Optoelectronics; Institute of Semiconductors; Chinese Academy of Sciences; Beijing 100083 P. R. China
3. Center of Materials Science and Optoelectronics Engineering; University of Chinese Academy of Sciences; Beijing 100049 China
4. School of Information Engineering; Minzu University of China; Beijing 100081 P. R. China
5. Institute for Advanced Interdisciplinary Research; Jinan University; Jinan 250022 P. R. China