1. Xinjiang Key Laboratory of Solid State Physics and Devices, Xinjiang University, Urumqi 830046, PR China
2. School of Physics and Technology, Xin Jiang University, Urumqi, Xinjiang 830046, China
3. School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083, China
4. Xinjiang Uygur Autonomous Region Research Institute of Measurement and Testing, Urumqi 830011, China