1. International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education Institute of Microscale Optoelectronics Shenzhen University Shenzhen 518060 China
2. College of Science Civil Aviation University of China Tianjin 300300 China
3. Department of Applied Physics The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong SAR China
4. Department of Engineering Physics Tsinghua University Beijing 100084 China
5. Physics Department Shanghai Key Laboratory of High Temperature Superconductors Shanghai University Shanghai 200444 China
6. Institute of Materials Research and Engineering A*STAR (Agency for Science Technology and Research) 2 Fusionopolis Way Singapore 138634 Singapore
7. Singapore Synchrotron Light Source National University of Singapore Singapore 117603 Singapore
8. Department of Physics National University of Singapore Singapore 117551 Singapore