1. Nanchang University, Department of Physics, Nanchang 330031, China
2. Nanchang University, Department of Physics, Nanchang 330031, ChinabChinese Academy of Science, Institute of Semiconductors, The State Key Laboratory on Integrated Optoelectronics, Beijing 100083, China
3. Nanchang University, Institute for Advanced Study, Nanchang 330031, China