1. Department of Electrical and Computer Engineering; National University of Singapore; 4 Engineering Drive 3 Singapore 117583 Singapore
2. Centre for Advanced 2D Materials; National University of Singapore; 6 Science Drive 2 Singapore 117543 Singapore
3. Department of Chemistry; National University of Singapore; 3 Science Drive 3 Singapore 117543 Singapore
4. NUSNNI-Nanocore; National University of Singapore; Singapore 117411 Singapore
5. Centre for Advanced 2D Materials and Graphene Research Centre; National University of Singapore; 6 Science Drive 2 Singapore 1175464 Singapore
6. National University of Singapore Graduate School for Integrative Sciences and Engineering; National University of Singapore; 28 Medical Drive Singapore 117456 Singapore