1. Department of Applied Physics and Materials Research Center The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong
2. Shenzhen Research Institute The Hong Kong Polytechnic University Shenzhen 518057 China
3. Solar Energy Research Institute The National University of Malaysia Bangi Selangor 43600 Malaysia
4. Nanomaterials Research Institute (NanoMaRi) Kanazawa University Kakuma Kanazawa 920‐1192 Japan
5. Institute of Sustainable Energy Universiti Tenaga Nasional (@The National Energy University) Jalan IKRAM‐UNITEN Kajang Selangor 43000 Malaysia
6. Graduate School of Materials Science Department of Materials Science Aoyama Gakuin University 4 Chome‐4‐25 Shibuya, Shibuya City Tokyo 150‐8366 Japan
7. Graduate School of Materials Science Nara Institute of Science and Technology 8916‐5 Takayama Ikoma Nara 630‐0192 Japan
8. Geballe Laboratory for Advanced Materials Department of Materials Science and Engineering Stanford University Stanford CA 94305 USA