1. Wuhan National Laboratory for Optoelectronics
2. School of Optical and Electronic Information
3. Huazhong University of Science and Technology
4. Wuhan 430074
5. China
6. Institute of Microelectronics
7. Tsinghua University
8. Beijing 100084
9. The State Key Laboratory of Material Processing and Die & Mould Technology
10. School of Materials Science and Engineering
11. Division of Materials Theory
12. Department of Physics and Astronomy
13. Uppsala University
14. Uppsala SE-75120
15. Sweden