1. Key Laboratory of Semiconductor Photovoltaic Technology and Energy Materials of Inner Mongolia Autonomous Region, School of Physical Science and Technology, Inner Mongolia University, 235 West Daxue Street, Hohhot 010021, China
2. College of Physics and Electronic Information, Inner Mongolia Minzu University, 536 Huolinhe Street West, Keerqin District, Tongliao 028000, China
3. Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, Aalto, Espoo FI-00076, Finland
4. Department of Material Science, Shenzhen MSU-BIT University, 1 University Park Road, Long gang District, Shenzhen, Guangdong 518000, China
5. Inner Mongolia Academy of Science and Technology, No. 2 Shandan Street, Saihan District, Hohhot, Inner Mongolia Autonomous Region 010021, China
6. School of Materials Science and Engineering, Oklahoma State University, 700 N. Greenwood Avenue, Tulsa, Oklahoma 74106, United States