1. Key Laboratory of Novel Thin Film Solar Cells
2. Division of Solar Energy Materials and Engineering
3. Institute of Plasma Physics
4. Chinese Academy of Sciences
5. Hefei 230031
6. Beijing Key Lab of Novel Thin Film Solar Cells
7. North China Electric Power University
8. Beijing
9. P. R. China
10. Laboratory for Photonics and Interfaces
11. Institution of Chemical Sciences and Engineering
12. School of Basic Sciences
13. Swiss Federal Institute of Technology
14. CH-1015 Lausanne