Few-particle energies versus geometry and composition of InxGa1-xAs/GaAs self-organized quantum dots
Few-particle energies versus geometry and composition of InxGa1-xAs/GaAs self-organized quantum dots
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DOI：
10.1103/physrevb.79.075443
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发表时间：
2009-02-01
影响因子：
3.7
通讯作者：
Bimberg, Dieter
中科院分区：
文献类型：
--
作者：
Schliwa, Andrei;Winkelnkemper, Momme;Bimberg, Dieter
结合八波段k中心点p理论，利用构型相互作用模型计算了大量实际量子点的激子、双激子和带电激子的能量。详细分析了量子点几何形状与组成、电子和空穴波函数的形状和位置、直接库仑能以及相关效应引起的变化之间的相互关系。量子点的大小、基本形状（圆形、方形或菱形）以及垂直和横向纵横比是不同的。研究了不同的平均成分和成分分布，如“小号形状”或各向同性的In梯度，这是由生长后退火过程引起的。结果表明，所得光谱特征对所有这些结构和化学参数都非常敏感。我们分析了它们之间的相互关系，以解决能带结构反演问题，从其光谱特征中获得有关量子点形态的信息。结果与现有实验数据进行了比较。
Energies of exciton, biexciton, and charged excitons for a large variety of realistic quantum dots are calculated using the configuration-interaction model in conjunction with eight-band k center dot p theory. The interrelation between quantum dot (QD) geometry and composition, the resulting shape and position of electron and hole wave functions, the direct Coulomb energies, and the changes introduced by correlation effects are analyzed in detail. The QD size, the base shape-being either circular, square, or rhombohedral-and the vertical and lateral aspect ratio are varied. Different average compositions and composition profiles, such as the "trumpet shape," or an isotropic In gradient resulting from postgrowth annealing processes are studied. The resulting spectroscopic signatures turn out to be very sensitive to all these structural and chemical parameters. We analyze their interrelation to address the band-structure inversion problem, gaining information on the QD morphology from its spectroscopic signature. The results are compared to available experimental data.