1. College of Electrical, Energy and Power Engineering, Yangzhou University, Yangzhou 225127, China
2. College of Electrical, Energy and Power Engineering, Yangzhou University, Yangzhou 225127, China; School of Material Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China
3. College of Physical Science and Technology, Institute of Optoelectronic Technology, Yangzhou University, Yangzhou 225002, China
4. School of Material Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China