1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100190, China
2. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
3. Institute of Microelectronics and Beijing National Research Center for Information Science and Technology (BNRIST), Tsinghua University, Beijing 100084, China
4. Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China