1. College of Physics and Energy
2. Shenzhen University
3. Shenzhen 518060
4. P. R. China
5. Department of Materials Science and NanoEngineering
6. Department of Chemistry, and the Smalley Institute for Nanoscale Science and Technology
7. Rice University
8. Houston
9. USA
10. Department of Electronic Engineering and Materials Science and Technology Research Center
11. The Chinese University of Hong Kong
12. N.T.
13. People's Republic of China