1. Department of Applied Physics, China Agricultural University, Beijing 100083, China
2. State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China
3. College of Science, China Agricultural University, Beijing 100083, China
4. Science and Technology on Reliability and Environment Engineering Laboratory, School of Reliability and Systems Engineering, Beihang University, Beijing 100191, China