1. Wuhan National Laboratory for Optoelectronics (WNLO) and School of Optical and Electronic InformationHuazhong University of Science and Technology (HUST) 1037 Luoyu Road 430074 Wuhan Hubei P. R. China
2. Shenzhen R&D Center of Huazhong University of Science and Technology Shenzhen 518000 P. R. China
3. School of Photovoltaic and Renewable Energy EngineeringUniversity of New South Wales Sydney NSW 2052 Australia
4. School of Optical and Electronic Information (SOEI)Huazhong University of Science and Technology (HUST) 1037 Luoyu Road 430074 Wuhan Hubei P. R. China
5. Shanghai Synchrotron Radiation FacilityShanghai Institute of Applied PhysicsChinese Academy of Sciences Shanghai P. R. China