1. Tianjin Key Laboratory for Photoelectric Materials and Devices, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, P. R. China
2. Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Tianjin University of Technology, Tianjin 300384, P. R. China
3. Chemical Engineering College, Hebei Normal University of Science and Technology, Qinhuangdao 066600, P. R. China