[1] South China Normal Univ, South China Acad Adv Optoelect, Inst Adv Mat, Guangdong Prov Key Lab Quantum Engn & Quantum Mat, Guangzhou 510006, Guangdong, Peoples R China
[2] Lanzhou Univ, Inst Phys Sci & Technol, Lanzhou 510006, Gansu, Peoples R China
[3] South China Normal Univ, South China Acad Adv Optoelect, Natl Ctr Int Res Green Optoelect, Guangzhou 510006, Guangdong, Peoples R China
[4] Nanjing Univ, Lab Solid State Microstruct, Nanjing 2100, Jiangsu, Peoples R China