Theoretical study of quantum confined Stark shift in InAs/GaAs quantum dots

• 来源期刊: 中国物理（英文版）
• 关键词: quantum dots plane-wave expansion self-assembled quantum confined Stark effect
• 年，卷（期）: 2004,（12）
• 页码范围: 2141-2146
• 页数: 6页
• 语种: 英文

摘要

The quantum confined Stark effect (QCSE) of the self-assembled InAs/GaAs quantum dots has been investigated theoretically. The ground-state transition energies for quantum dots in the shape of a cube, pyramid or "truncated pyramid" are calculated and analysed. We use a method based on the Green function technique for calculating the strain in quantum dots and an efficient plane-wave envelope-function technique to determine the ground-state electronic structure of them with different shapes. The symmetry of quantum dots is broken by the effect of strain. So the properties of carriers show different behaviours from the traditional quantum device. Based on these results, we also calculate permanent built-in dipole moments and compare them with recent experimental data. Our results demonstrate that the measured Stark effect in self-assembled InAs/GaAs quantum dot structures can be explained by including linear grading.