1. Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
2. Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR 999077, China
3. Department of Chemistry, Southern University of Science and Technology, Shenzhen 518000, China
4. National Synchrotron Light Source II, Brookhaven National Lab, Upton, New York 11973, United States
5. Department of Materials Science and Engineering, National University of Singapore, Singapore 117576, Singapore
6. School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong 518172, China