1. Shenzhen
Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
2. State Key Laboratory of Solid Lubrication,
Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, China
3. Graduate School of the Chinese Academy of Sciences, Beijing, China
4. School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States
5. Department
of Electronics Engineering, The Chinese University of Hong Kong, Hong Kong, China