[1] Sun Yat Sen Univ, Sch Phys, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Guangdong, Peoples R China
[2] Peking Univ, Sch Phys, State Key Lab Mesoscop Phys & Frontiers Sci, Ctr Nanooptoelect, Beijing 100871, Peoples R China
[3] Jilin Univ, Coll Elect Sci & Engn, State Key Lab Integrated Optoelect, Changchun 130012, Peoples R China