1. School of Materials and Energy
2. Guangdong University of Technology
3. Guangzhou
4. P. R. China
5. State Key Laboratory of Optoelectronic Materials and Technologies
6. Nanotechnology Research Center
7. School of Materials Science & Engineering
8. Sun Yat-sen University
9. Guangzhou 510275
10. Institute of Semiconductors
11. South China Normal University
12. State Key Laboratory for Superlattices and Microstructures