1. State Key Laboratory of Applied Organic Chemistry (Lanzhou University), Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China
2. School of Physical Science & Technology, Lanzhou University, Lanzhou 730000, People's Republic of China
3. New Energy (Photovoltaic) Industry Research Centre, Qinghai University, Xining 810006, People's Republic of China