Coulomb-induced emission dynamics and self-consistent calculations of type-II Sb-containing quantum dot systems
Coulomb-induced emission dynamics and self-consistent calculations of type-II Sb-containing quantum dot systems
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II型含锑量子点系统的库仑诱导发射动力学和自洽计算
DOI：
10.1103/physrevb.85.035432
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发表时间：
2012
影响因子：
3.7
通讯作者：
D. Huffaker
中科院分区：
文献类型：
--
作者：
K. Gradkowski;T. Ochalski;N. Pavarelli;Huiyun Liu;J. Tatebayashi;David P. Williams;D. Mowbray;G. Huyet;D. Huffaker
研究了高激发密度下库仑相互作用对含Sb量子点系统发射动力学的影响。研究了两种不同的II型限制：使用GaAsSb量子阱覆盖的InAs/GaAs量子点（IIa型）的受限电子与非受限空穴，以及使用InGaAs量子阱覆盖的GaSb/GaAs量子点（IIb型）的受限空穴与非受限电子。时间分辨的光致发光实验与自洽的数值计算进行了比较，使用8-bandk·p模型。在这两种结构中，我们观察到一个显着的蓝移的发射和波长依赖的辐射寿命，但与两个系统之间的显着的定量差异：在类型-IIa，蓝移是12毫电子伏的寿命从1.4 ns到2.0 ns的变化，并在类型-IIb，蓝移是63毫电子伏的寿命从100 ps到23 ns的变化。我们提出了一个全面的解释库仑引起的变化的载波函数和限制电位的实验数据的所有重要功能，与电子和空穴的单独限制是一个至关重要的因素。
This paper investigates the effects of Coulomb interactions on the emission dynamics of Sb-containing quantum dot (QD) systems under high excitation densities. Two different type-II confinements are studied: confined electrons with unconfined holes using InAs/GaAs QDs capped with a GaAsSb quantum well (type-IIa), and confined holes with unconfined electrons using GaSb/GaAs QDs capped with an InGaAs quantum well (type-IIb). Time-resolved photoluminescence experiments are compared with self-consistent numerical calculations using an 8-bandk·pmodel. In both structures, we observe a significant blueshift of emission and wavelength-dependent radiative lifetimes, but with marked quantitative differences between the two systems: in the type-IIa, the blueshift is 12 meV with a change in lifetime from 1.4 ns to 2.0 ns, and in the type-IIb, the blueshift is 63 meV with lifetime change from 100 ps to 23 ns. We present a comprehensive explanation of all the important features of the experimental data in terms of Coulomb-induced changes to the carrier wave functions and confining potentials, with the separate confinement of the electrons and holes being a crucial factor.