1. School of Electrical Engineering and Automation, Tianjin Key Laboratory of Advanced Electrical Engineering and Energy Technology, Tianjin Polytechnic University, Tianjin 300387, China
2. Tianjin San’an Optoelectronics Co., LTD., Tianjin 300384, China
3. Institute of Photoelectronics, Tianjin Key Laboratory of Photoelectronic Thin-film Devices and Technique, Nankai University, Tianjin 300071, China