1. CINTRA - CNRS/NTU/Thales; UMI 3288; 50 Nanyang Drive 637553 Singapore
2. School of Electrical and Electronics Engineering; Nanyang Technological University; 50 Nanyang Avenue 639798 Singapore
3. Department of Chemical Engineering; Graduate School of Engineering; Hiroshima University; Higashi-Hiroshima 739-8527 Japan
4. Department of Physics; Faculty of Mathematics and Natural Sciences; Institut Teknologi Bandung; Bandung 40132 Indonesia
5. Department of Chemistry; National University of Singapore; 117543 Singapore
6. Centre for Advanced 2D Materials and Graphene Research Centre; National University of Singapore; 6 Science Drive 2 117546 Singapore
7. Department of Physics; National University of Singapore; 117542 Singapore
8. Physics Research Center; The Indonesian Institute of Sciences; Puspitek, Serpong Banten 15314 Indonesia