1. College of Materials and Chemical Engineering, Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials, China Three Gorges University, Yichang 443002, P. R. China
2. Hubei Three Gorges Laboratory, Yichang 443007, P. R. China
3. College of Electrical Engineering & New Energy, China Three Gorges University, Yichang 443002, P. R. China