1. School of Physics and Electronics
2. Hunan University
3. Changsha 410082
4. P. R. China
5. Faculty of Technology
6. University of Oulu
7. Oulu 90014
8. Finland
9. Panzhihua University
10. School of Chemistry
11. Physics and Mechanical Engineering
12. Queensland University of Technology
13. Brisbane
14. Australia
15. Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education)