Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - An investigation of exciton behavior in type-II self-assembled GaSb/GaAs quantum dots
AU - Qiu, Feng
AU - Qiu, Weiyang
AU - Li, Yulian
AU - Wang, Xingjun
AU - Zhang, Yun
AU - Zhou, Xiaohao
AU - Lv, Yingfei
AU - Sun, Yan
AU - Deng, Huiyong
AU - Hu, Shuhong
AU - Dai, Ning
AU - Wang, Chong
AU - Yang, Yu
AU - Zhuang, Qiandong
AU - Hayne, Manus
AU - Krier, A.
PY - 2016/2/12
Y1 - 2016/2/12
N2 - We report the investigation of exciton dynamics in type-II self-assembled GaSb/GaAs quantum dots. The GaSb/GaAs quantum dots (QDs) were grown using a modified liquid phase epitaxy technique. Statistical size distributions of the uncapped QDs were investigated experimentally by field-emission scanning electron microscopy (SEM) and atomic force microscopy (AFM), and theoretically by an eight-band k . p calculation, which demonstrated a dissolution effect. Furthermore, the low-temperature luminescence spectra of type-II GaSb/GaAs QDs with a thick capping layer exhibit well-resolved emission bands and LO-phonon-assisted transitions in the GaSb wetting layer. However, the luminescence lines quench at temperatures above 250 K, which is attributed to the weak quantum confinement of electrons participating in indirect exciton recombination. It was demonstrated that the room temperature stability of the excitons in type-II GaSb/GaAs QDs could be achieved by growing thin a capping layer, which provides strong quantum confinement in the conduction band and enhances the electron-hole Coulomb interaction, stabilizing the excitons.
AB - We report the investigation of exciton dynamics in type-II self-assembled GaSb/GaAs quantum dots. The GaSb/GaAs quantum dots (QDs) were grown using a modified liquid phase epitaxy technique. Statistical size distributions of the uncapped QDs were investigated experimentally by field-emission scanning electron microscopy (SEM) and atomic force microscopy (AFM), and theoretically by an eight-band k . p calculation, which demonstrated a dissolution effect. Furthermore, the low-temperature luminescence spectra of type-II GaSb/GaAs QDs with a thick capping layer exhibit well-resolved emission bands and LO-phonon-assisted transitions in the GaSb wetting layer. However, the luminescence lines quench at temperatures above 250 K, which is attributed to the weak quantum confinement of electrons participating in indirect exciton recombination. It was demonstrated that the room temperature stability of the excitons in type-II GaSb/GaAs QDs could be achieved by growing thin a capping layer, which provides strong quantum confinement in the conduction band and enhances the electron-hole Coulomb interaction, stabilizing the excitons.
KW - GaSb quantum dots
KW - liquid phase epitaxy
KW - indirect exciton
KW - weak quantum confinement
KW - LIQUID-PHASE EPITAXY
KW - RECOMBINATION
KW - LOCALIZATION
KW - GROWTH
U2 - 10.1088/0957-4484/27/6/065602
DO - 10.1088/0957-4484/27/6/065602
M3 - Journal article
VL - 27
JO - Nanotechnology
JF - Nanotechnology
SN - 0957-4484
IS - 6
M1 - 065602
ER -