1. School of Chemistry, Guangzhou Key Laboratory of Materials for Energy Conversion and Storage, Guangdong Provincial Engineering Technology Research Center for Materials for Energy Conversion and Storage, South China Normal University (SCNU), Guangzhou 510006, P. R. China
2. Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
3. Spallation Neutron Source Science Center, Dongguan 523803, China
4. Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
5. Siyuan Laboratory, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials, Department of Physics, Jinan University (JNU), Guangzhou 510632, P. R. China
6. Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology (SCUT), Guangzhou 510640, P. R. China