1. Key Laboratory of Atomic and Molecular Physics & Functional Materials of Gansu Province College of Physics and Electronic Engineering Northwest Normal University Lanzhou 730070 China
2. State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 730000 China
3. Institute of Optoelectronic Materials and Devices Faculty of Materials Metallurgy and Chemistry Jiangxi University of Science and Technology Ganzhou 341000 China