1. Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
2. Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, Singapore, Singapore 639977
3. College of Physics and Energy, Shenzhen University, Shenzhen 518060, China
4. Department of Chemistry, City University of Hong Kong, Kowloon, Hong Kong, China
5. Department of Physics, University of Hong Kong, Hong Kong, China
6. MajuLab, CNRS-UNS-NUS-NTU International Joint Research Unit, UMI 3654, Singapore 639798
7. NOVITAS, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798