1. Laboratory for Advanced Interfacial Materials and Devices; Institute of Textiles and Clothing; the Hong Kong Polytechnic University; Hong Kong China
2. Energy Materials and Surface Sciences Unit (EMSS); Okinawa Institute of Science and Technology Graduate University (OIST); 1919-1 Tancha Onna-son Okinawa 904-0497 Japan
3. Institute for Solar Energy Systems; Sun Yat-Sen University; 510275 Guangzhou Guangdong Province P. R. China
4. Department of Electronic and Information Engineering; the Hong Kong Polytechnic University; Hong Kong China