1. Department of Physics and Electronic Engineering, Yancheng Teachers University, Yancheng 224002, China
2. School of Applied Physics and Materials, Wuyi University, Jiangmen 529020, China
3. Walker Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712, United States
4. Yunnan Key Laboratory for Micro/Nano Materials & Technology, National Center for International Research on Photoelectric and Energy Materials, School of Materials and Energy, Yunnan University, Kunming 650091, China