1. Department
of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
2. Institute of Materials
Research and Engineering, A*STAR (Agency for Science, Technology and
Research), 2 Fusionopolis Way, Singapore 138634, Singapore
3. Department
of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117575, Singapore
4. Centre for Advanced
2D Materials and Graphene Research Centre, National University of Singapore, 6 Science
Drive 2, Singapore 117546, Singapore