[1] Shenzhen Univ, Coll Elect & Informat Engn, Shenzhen 518060, Peoples R China
[2] Shenzhen Univ, Inst Microscale Optoelect IMO, Shenzhen 518060, Peoples R China
[3] Hong Kong Univ Sci & Technol, State Key Lab Adv Displays & Optoelect Technol, Kowloon, Clear Water Bay, Hong Kong, Peoples R China