1. State Key Laboratory for Physical Chemistry of Solid Surfaces
2. Department of Chemistry
3. Xiamen University
4. Xiamen
5. P. R. China
6. Department of Mechanical and Biomedical Engineering
7. City University of Hong Kong
8. Hong Kong
9. School of Materials Science and Engineering
10. Georgia Institute of Technology
11. Semiconductor Photonics Research Center
12. Department of Physics
13. Atlanta 30332-0245
14. USA