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. Key Laboratory for Colloid and Interface Chemistry of State Education Ministry
7. School of Chemistry and Chemical Engineering
8. Shandong University
9. Jinan 250100
10. School of Materials Science and Engineering
11. Tianjin Key Laboratory of Composite and Functional Materials
12. Tianjin University
13. Tianjin
14. China