1. State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano‐optoelectronics School of Physics Peking University Beijing 100871 P. R. China
2. Songshan Lake Materials Laboratory Dongguan Guangdong 523808 P. R. China
3. Electron Microscopy Laboratory School of Physics Peking University Beijing 100871 P. R. China
4. Department of Materials Science and Engineering Chonnam National University Gwangju 61186 Republic of Korea
5. Key Laboratory of Semiconductor Materials Science and Beijing Key Laboratory of Low‐dimensional Semiconductor Materials and Devices Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 P. R. China
6. Advanced Micro‐Fabrication Equipment Inc Shanghai 201201 P. R. China
7. Collaborative Innovation Center of Quantum Matter Beijing 100871 P. R. China
8. Peking University Yangtze Delta Institute of Optoelectronics Nantong Jiangsu 226010 China