1. Department of Chemistry and Center of Super-Diamond & Advanced Films (COSDAF), City University of Hong Kong, Kowloon 999077, Hong Kong, China
2. Physics Department, School of Physics and Electronic Electrical Engineering & and Jiangsu Key Laboratory for Chemistry of Low-Dimensional Materials, Huaiyin Normal University, Huaian 223300, China
3. Department of Energy Conversion and Storage, Technical University of Denmark, Fysikvej, 2800 Kgs. Lyngby, Denmark
4. Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
5. Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon 999077, Hong Kong, China