1. School of Materials Science and Engineering
2. Central South University
3. Changsha 410083
4. P. R. China
5. Guangxi Key Laboratory of Information Materials
6. Guilin University of Electronic Technology
7. Guilin 541004
8. Skolkovo Institute of Science and Technology
9. Skolkovo Innovation Center
10. Moscow 143026
11. Russia
12. Moscow Institute of Physics and Technology