[1] S China Normal Univ, Inst Optoelect Mat & Technol, Guangzhou 510631, Guangdong, Peoples R China
[2] Natl Taiwan Univ, Inst Photon & Optoelect, Dept Elect Engn, Taipei 10617, Taiwan
[3] Natl Taiwan Univ, Ctr Emerging Mat & Adv Devices, Taipei 10617, Taiwan
[4] Sun Yat Sen Univ, State Key Lab Optoelect Mat & Technol, Guangzhou 510275, Guangdong, Peoples R China
[5] Sun Yat Sen Univ, Sch Phys & Engn, Guangzhou 510275, Guangdong, Peoples R China
[6] Indiana Univ Penn, Dept Phys, Indiana, PA 15705 USA
[7] Shenzhen Univ, Coll Phys Sci & Technol, Shenzhen 518060, Peoples R China
[8] Natl Cheng Kung Univ, Dept Mat Sci & Engn, Tainan 701, Taiwan
[9] Northwestern Polytech Univ, Sch Sci, Minist Educ, Key Lab Space Appl Phys & Chem, Xian 710072, Peoples R China
[10] Northwestern Polytech Univ, Sch Sci, Shaanxi Key Lab Opt Informat Technol, Xian 710072, Peoples R China