1. School of Electrical and Electronic Engineering
2. Nanyang Technological University
3. Singapore 639798
4. Singapore
5. Institute of Materials Research and Engineering (IMRE)
6. Agency of Science, Technology and Research (A*STAR)
7. Singapore 138634
8. Department of Physics
9. National University of Singapore
10. Singapore 117542
11. Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC)