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