1. College of Information Science & Electronic Engineering State Key Laboratory of Silicon Materials Zhejiang University Hangzhou Zhejiang 310027 China
2. Cambridge Graphene Centre University of Cambridge Cambridge CB3 0FA UK
3. National Laboratory of Solid State Microstructures School of Electronic Science and Engineering Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 China
4. School of Materials Science and Engineering Zhejiang University Hangzhou Zhejiang 310027 China
5. Institute of Applied Mechanics Zhejiang University Hangzhou Zhejiang 310027 China
6. Rowland Institute Harvard University 100 Edwin H Land Blvd Cambridge MA 02142 USA
7. College of Nanoscale Science and Engineering State University of New York Albany NY 12203 USA
8. Department of Chemistry and Biochemistry and California Nanosystems Institute University of California Los Angeles CA 90095 USA
9. State Key Laboratory of Superlattices and Micro Structures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China
10. National Laboratory for Infrared Physics Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200083 China
11. Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials School of Electronic Science and Engineering Nanjing University Nanjing 210093 China