1. Department of Physics, Changzhi University, Changzhi 046011, China
2. School of Science and Technology, Northwestern Polytechnical University, Xi’an 710072, China
3. Research Institute of Opto-Mechatronics Industry, Jincheng 048000, China
4. Shanxi Key Laboratory of Advanced Semiconductor Optoelectronic Devices and Integrated Systems, Jincheng 048000, China