1. State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200433, China
2. SHU-SolarE R&D Lab, Department of Physics, College of Sciences, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
3. Department of Electronic Information Materials, School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China
4. Key Laboratory of Wide Band-Gap Semiconductor Materials and Devices, Xidian University, Xi’an 710071, China