1. South China Academy of Advanced Optoelectronics & International Academy of Optoelectronics at Zhaoqing South China Normal University Guangzhou 510006 China
2. Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 P. R. China
3. School of Materials Science and Engineering, State Key Laboratory of Reliability and Intelligence of Electrical Equipment Hebei University of Technology Tianjin 300130 China
4. Department of Chemical Engineering University of Waterloo Waterloo, ON N2L 3G1 Canada