1. Hunan Key Laboratory of Two-Dimensional Materials and State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China
2. School of Physics and Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 211189, China
3. School of Physics and Electronics, Hunan University, Changsha 410082, China
4. College of Semiconductors (College of Integrated Circuits), Hunan University, Changsha 410082, China