1. School of Physics and Microelectronics, Key Laboratory of Materials Physics of Ministry of Education, Zhengzhou University, Daxue Road 75, Zhengzhou 450052, China
2. College of Physics and Electronic Engineering, Zhengzhou University of Light Industry, Kexue Road 136, Zhengzhou 450001, China
3. Key Laboratory of Materials Physics of Ministry of Education, Zhengzhou University, Daxue Road 75, Zhengzhou 450052, China
4. State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Qianjin Street 2699, Changchun 130012, China