1. Shenzhen Engineering Center for the Fabrication of Two‐Dimensional Atomic Crystals Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 P. R. China
2. University of Chinese Academy of Sciences Beijing 100049 P. R. China
3. Department of Physics Department of Materials Science and Engineering, and Department of Biomedical Engineering City University of Hong Kong Tat Chee Avenue, Kowloon Hong Kong China