Affiliation: | 1. Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong (P.R. China);2. Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong (P.R. China);3. Department of Physics, Hong Kong Baptist University, Waterloo Road, Kowloon Tong, Hong Kong (P.R. China);4. Department of Electronic and Information Engineering, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong (P.R. China) |