1. Institute of Materials Research and Engineering, Agency for Science, Technology and Research, 138634, Singapore;
2. Centre for Advanced 2D Materials, National University of Singapore, 117546, Singapore;
3. Department of Chemistry, National University of Singapore, 117542, Singapore;
4. Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, Institute of Nanoscience, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
5. Department of Electrical and Computer Engineering, National University of Singapore, 117583, Singapore;
6. Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Taipa, Macau, China;
7. School of Physics and Technology, Nanjing Normal University, Nanjing 210023, China;
8. Department of Physics, National University of Singapore, 117542, Singapore;
9. Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan;
10. Institute of High Performance Computing, Agency for Science, Technology and Research, 138632, Singapore;
11. Shenzhen University-National University of Singapore Collaborative Innovation Center for Optoelectronic Science and Technology, Shenzhen University, Shenzhen, 518060, China;
12. Department of Materials Science and Engineering, Nanyang Technological University, 639798, Singapore