Complex emission dynamics of type-II GaSb/GaAs quantum dots
Complex emission dynamics of type-II GaSb/GaAs quantum dots
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DOI：
10.1063/1.3202419
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发表时间：
2009-08-10
影响因子：
4
通讯作者：
Huffaker, Diana L.
中科院分区：
文献类型：
--
作者：
Gradkowski, Kamil;Pavarelli, Nicola;Huffaker, Diana L.
利用时间分辨光致发光技术研究了GaSb/GaAs量子点系统的光学特性。在这种ii型异质结构中，不同种类的载流子在空间上是分离的，因此可以观察到发射波长和衰变时间尺度的平滑演变。从100ps到23ns的时间尺度变化，同时测量到170nm的波长位移。这些现象可以用载流子密度的变化来解释，载流子密度的变化导致了光跃迁概率的改变以及发射向高能量方向的偏移。
Optical properties of the GaSb/GaAs quantum dot system are investigated using a time-resolved photoluminescence technique. In this type-II heterostructure the carriers of different species are spatially separated and, as a consequence, a smooth evolution of both the emission wavelength and decay timescale is observed. A wavelength shift of 170 nm is measured simultaneously with the progressive timescale change from 100 ps to 23 ns. These phenomena are explained by the evolution of the carrier density, which brings a modification to the optical transition probability as well as the shift in the emission toward the higher energies.