1. Key Laboratory for Micro-/Nano-Optoelectronic Devices of the Ministry of Education
2. School of Physics and Electronics
3. Hunan University
4. Changsha 410082
5. P. R. China
6. State Key Laboratory of Chem-/Bio-Sensing and Chemometrics
7. College of Chemistry and Chemical Engineering
8. Institute for Superconducting and Electronic Materials
9. University of Wollongong
10. Wollongong
11. Australia