1. Shenzhen Key Laboratory of Flexible Memory Materials and Devices
2. College of Physics and Optoelectronic Engineering
3. Shenzhen University
4. Guangdong 518060
5. People's Republic of China
6. CAS Key Laboratory of Nanosystem and Hierarchical Fabrication
7. CAS Center for Excellence in Nanoscience
8. National Center for Nanoscience and Technology
9. Beijing 100190
10. State Key Laboratory of Biochemical Engineering
11. Institute of Process Engineering
12. Chinese Academy of Sciences
13. Chinese Academy of Science
14. North China Power Electric University
15. Beijing 102206