1. Key Laboratory for Organic Electronics and Information Displays, Nanjing University of Posts & Telecommunications, Institute of Advanced Materials (IAM), 9 Wenyuan Road, Nanjing 210023, China
2. Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
3. Department of Applied Physics, School of Science, Tianjin University, Level 2, Building 32, Beiyangyuan Campus Tianjin University, No. 135, Yaguan Road, Haihe Education Park, Jinnan District, Tianjin 300354, P. R. China