1. Institute of Materials Research and Engineering (IMRE) Agency for Science Technology and Research (A*STAR) 2 Fusionopolis Way, Innovis #08‐03 Singapore 138634 Singapore
2. Department of Chemistry University of Sheffield Brook Hill Sheffield S3 7HF UK
3. Pennsylvania State University State College PA 16801 USA
4. Singapore Institute of Food and Biotechnology Innovation Agency for Science Technology and Research (A*STAR) 31 Biopolis Way, #01‐02 Nanos Singapore 138669 Singapore
5. Department of Chemistry 3 Science Drive 3 National University of Singapore Singapore 117543 Singapore
6. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
7. Department of Physics National University of Singapore Singapore 117551 Singapore
8. Department of Electrical and Computer Engineering National University of Singapore 4 Engineering Drive 3 Singapore 117583 Singapore
9. Department of Materials Science and Engineering National University of Singapore 9 Engineering Drive 1 Singapore 117575 Singapore