1. College of Materials Science and Engineering & Institute of New Energy and Low-carbon Technology, Sichuan University, Chengdu 610064, P.R. China
2. Chengdu Textile College, Chengdu 611731, P.R. China
3. Engineering Research Center of Alternative Energy Materials & Devices, Ministry of Education, Chengdu 610065, P.R. China
4. College of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu 610225, P.R. China