1. Institute of Micro-Nano Optoelectronics and Terahertz Technology, School of Mechanical Engineering, Jiangsu University, Zhenjiang 212013, People's Republic of China
2. Institute for Energy Research, Jiangsu University, Zhenjiang 212013, People's Republic of China
3. College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, People's Republic of China