1. School of Microelectronics Hefei University of Technology Hefei 230009 China
2. School of Physics Hefei University of Technology Hefei 230009 China
3. School of Materials Science and Engineering and Anhui Provincial Key Laboratory of Advanced Functional Materials and Devices Hefei University of Technology Hefei 230009 China
4. Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science College of Chemistry and Chemical Engineering Central South University Changsha 410083 China
5. School of Physics and Microelectronics Zhengzhou University Zhengzhou 450052 China