1. School of Physics, Northwest University, Xi’an 710069, P. R. China
2. School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
3. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, Hubei, China
4. Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory, Xianhu Hydrogen Valley, Foshan 528200, Guangdong, China
5. Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics, Chinese Academy of Science, Hefei 230031, P. R. China
6. Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis #08-03, Singapore 138634, Republic of Singapore
7. Singapore Institute of Manufacturing Technology (SIMTech), 2 Fusionopolis Way, #08-04 Innovis, Singapore 138634, Singapore
8. Department of Electronic Engineering, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, SAR 999077, China