1. State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing 100871, China
2. School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China
3. Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
4. School of Physical Science and Technology, Yunnan University, Kunming 650091, China
5. Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
6. Peking University Yangtze Delta Institute of Optoelectronics, Nantong 226010, China