[1] Chinese Acad Sci, Changchun Inst Opt Fine Mech & Phys, Bimberg Sino German Green Photon Res Ctr, Changchun 130033, Jilin, Peoples R China
[2] Univ Chinese Acad Sci, Beijing 100049, Peoples R China
[3] Chinese Acad Sci, Changchun Inst Opt Fine Mech & Phys, State Key Lab Luminescence & Applicat, Changchun 130033, Jilin, Peoples R China
[4] Tech Univ Berlin, Inst Solid State Phys, Ctr Nanoopt, D-10623 Berlin, Germany