1. School of Physics
2. State Key Laboratory of Crystal Materials
3. Shandong University
4. Jinan 250100
5. China
6. Helmholtz-Zentrum Dresden-Rossendorf
7. Institute of Ion Beam and Materials Research
8. 01328 Dresden
9. Germany
10. Hunan Key Laboratory of Micro-Nano Energy Materials and Devices
11. Laboratory for Quantum Engineering and Micro-Nano Energy Technology and School of Physics and Optoelectronics
12. Xiangtan University
13. Xiangtan
14. People's Republic of China
15. Department of Applied Physics