1. Center of Nanomaterials for Renewable Energy, State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, PR China
2. CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, CAS Research/Education Center for Excellence in Molecular Sciences, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, PR China
3. University of Chinese Academy of Sciences, Beijing 100049, PR China
4. Jiangsu Jufeng New Energy Technology Co. Ltd., Changzhou, Jiangsu 213166, PR China
5. MOE Key Laboratory for UV Light-Emitting Materials and Technology, and Department of Physics, Northeast Normal University, Changchun, Jilin 130024, PR China