1. Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410114, China
2. Hunan Institute of Food Quality Supervision Inspection and Research, Changsha 410111, China
3. Department of Physics, Key Lab for Low-Dimensional Structures and Quantum Manipulation (Ministry of Education), Hunan Normal University, Changsha 410081, China
4. College of Materials Science and Engineering, Changsha University of Science & Technology, Changsha 410114, China