1. Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials, Ministry of Education. Anhui Graphene Engineering Laboratory, Anhui University, Hefei, Anhui 230601, China
2. Hefei National Laboratory for Physical Sciences at the Microscale, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
3. Department of Applied Physics, School of Science, Nanjing University of Science and Technology, Nanjing, 210094, China