1. Department of Physics and Materials Science
2. City University of Hong Kong
3. Kowloon, China
4. Wuhan National Laboratory for Optoelectronics
5. Huazhong University of Science and Technology
6. School of materials and metallurgy
7. Wuhan University of Science and Technology
8. Wuhan 430081, China
9. State Key Laboratory of Military Stomatology
10. Department of Periodontology
11. School of Stomatology
12. The Fourth Military Medical University
13. Xi'an 710032, China