1. School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, P. R. China
2. College of Optoelectronic Engineering, Key Laboratory of Optoelectronic Technology and Systems, Ministry of Education, Key Disciplines Lab of Novel Micro-Nano Devices and System Technology, Chongqing University, Chongqing 400044, P. R. China