1. New Energy Research Institute, School of
Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou, Guangdong 510006, China
2. State Key
Laboratory of Optoelectronic Materials and Technologies, School of
Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
3. School of
Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, Georgia 30332-0245, United States