1. CAS Key Laboratory of Standardization and Measurement for Nanotechnology
2. CAS Centre for Excellence in Nanoscience
3. National Centre for Nanoscience and Technology
4. Beijing 100190
5. People's Republic of China
6. Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices
7. Department of Physics
8. Renmin University of China
9. Beijing 100872
10. College of Electronic Science and Engineering
11. Nanjing University of Posts and Telecommunications
12. Nanjing 210046
13. Key Laboratory of Inorganic Functional Materials and Devices
14. Shanghai Institute of Ceramics
15. Chinese Academy of Sciences
16. Shanghai 200050