Influence of In/Ga intermixing on the optical properties of InGaAs/GaAs quantum dots
Influence of In/Ga intermixing on the optical properties of InGaAs/GaAs quantum dots
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DOI：
10.1016/s0022-0248(98)00698-8
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发表时间：
1998-12-01
影响因子：
1.8
通讯作者：
Bimberg, D
中科院分区：
文献类型：
--
作者：
Heinrichsdorff, F;Grundmann, M;Bimberg, D
我们报告的影响，热退火的掩埋InGaAs量子点（QD）的本征态能量和它们的不均匀加宽由于尺寸波动。应用退火温度（T-A）高达700摄氏度，持续30分钟的结果在一个蓝移的QD基态发光的150 meV伴随着强烈的减少子能级分离和不均匀的加宽。在同一时间的润湿层发光只有轻微的位移，导致在强烈降低的量子点的局域化能量。随着退火温度的升高，由于量子点的尺寸分布的光致发光峰展宽显示出明显的最大值，随后降低到低于生长的量子点的值。这些观察定性同意计算一个简单的模型系统的球形量子点假设Fickian相互扩散的点和屏障材料。我们的研究结果表明，生长温度（T-Gr）后施加的量子点沉积强烈影响其性能。因此，为了在InGaAs/GaAs系统中制造基于QD的器件，必须对TGr的选择进行折衷，以便实现QD中的高载流子局域化能量（低T-Gr）和盖层的高材料质量（高T-Gr）。(C)1998 Elsevier Science B. V.保留所有权利。
We report on the impact of thermal annealing of buried InGaAs quantum dots (QDs) on the eigenstate energies and their inhomogeneous broadening due to size fluctuations. Application of annealing temperatures (T-A) of up to 700 degrees C for 30 min results in a blue shift of the QD ground state luminescence of 150 meV accompanied by a strong reduction of sublevel separation and inhomogeneous broadening. At the same time the wetting layer luminescence is only slightly shifted, resulting in a strongly decreased localization energy of the QDs. With increasing annealing temperature the photoluminescence peak broadening due to the QDs size distribution shows a distinct maximum and subsequently decreases below the value of as grown QDs. These observations qualitatively agree with calculations for a simple model system of spherical QDs assuming Fickian interdiffusion of dot and barrier material. Our results demonstrate that the growth temperatures (T-Gr) applied after deposition of the QDs strongly affect their properties. Thus for fabrication of QD based devices in the InGaAs/GaAs system a compromise for the choice of TGr has to be made in order to achieve both high carrier localization energies in the QDs (low T-Gr) and high material quality of the cap layers (high T-Gr). (C) 1998 Elsevier Science B.V. All rights reserved.