1. Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
2. Huadian Electric Power Research Institute Co., LTD, Hangzhou, Zhejiang 310030, PR China