1. School of Material Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332–0245, USA.
2. State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027, China.
3. Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Institute of Functional Nano and Soft Materials, Soochow University, Suzhou, Jiangsu 215123, China.
4. Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
5. Department of Applied Physics, Chongqing University, Chongqing 400044, China.
6. School of Material Science and Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116, China.
7. Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences; National Center for Nanoscience and Technology, Beijing 100083, China.