1. Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, Laboratory for Quantum Engineering and Micro-Nano Energy Technology, School of Physics and Optoelectronics, Xiangtan University, Hunan 411105, People's Republic of China
2. School of Physics and Optoelectronic Engineering, Shandong University of Technology, Zibo, Shandong 255100, People's Republic of China