1. Department of Materials Science and Engineering & CAS Key Laboratory of Materials for Energy Conversion
2. University of Science and Technology of China
3. Hefei 230026, China
4. Wuxi Graphene Technologies Co., Ltd
5. Wuxi 214174, China
6. Jiangnan Graphene Research Institute
7. Changzhou 213149, China
8. National Synchrotron Radiation Research Center
9. Hsinchu 300, Taiwan
10. Department of Physics
11. Tamkang University
12. New Taipei City 25137, Taiwan