1. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link 637371 Singapore
2. Interdisciplinary Graduate School Block S2 ‐ B3a ‐ 01, 50 Nanyang Avenue 639798 Singapore
3. School of Materials Science and Engineering Nanyang Technological University Block N4.1, 50 Nanyang Avenue 639798 Singapore
4. Energy Research Institute @NTU (ERI@N) Research Techno Plaza, X‐Frontier Block, Level 5, 50 Nanyang Drive637553 Singapore
5. Institute of Materials Research and Engineering (IMRE) A*STAR 2 Fusionopolis Way, Innovis, #08‐03 138634 Singapore