[1] City Univ Hong Kong, Dept Phys & Mat Sci, Kowloon, Hong Kong, Peoples R China
[2] City Univ Hong Kong, Ctr Funct Photon CFP, Kowloon, Hong Kong, Peoples R China
[3] City Univ Hong Kong, Ctr Super Diamond & Adv Films COSDAF, Kowloon, Hong Kong, Peoples R China
[4] Hong Kong Polytech Univ, Dept Appl Phys, Kowloon, Hong Kong, Peoples R China
[5] Hong Kong Polytech Univ, Mat Res Ctr, Kowloon, Hong Kong, Peoples R China
[6] Hong Kong Univ Sci & Technol, Dept Phys, Hong Kong, Hong Kong, Peoples R China