1. Center for Nanochemistry, Beijing Science and Engineering Center for Nanocarbons, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
2. State Key Laboratory for Mesoscopic Physics, Academy for Advanced Interdisciplinary Studies, School of Physics, Peking University, Beijing 100871, China
3. Beijing Graphene Institute (BGI), Beijing 100095, China
4. Department of Biomedical Engineering, Academy for Advanced Interdisciplinary Studies, College of Engineering, Peking University, Beijing 100871, China
5. Physics Research Center for Two-Dimensional Optoelectronic Materials and Devices, School of Physics and Electronics, Henan University, Kaifeng 475004, China