Understanding Polarization Properties of InAs Quantum Dots by Atomistic Modeling of Growth Dynamics

TL;DR

This paper presents an atomistic growth model for InAs quantum dots with a core-shell composition profile, explaining polarization properties and strain effects, validated by experimental data.

Contribution

It introduces a realistic double-region composition model for InAs quantum dots that accounts for atomic-scale growth phenomena and strain energy considerations.

Findings

The model reproduces experimental polarization data accurately.

The two-region composition model results in lower strain energies.

Atomic-scale phenomena significantly influence quantum dot polarization properties.

Abstract

A model for realistic InAs quantum dot composition profile is proposed and analyzed, consisting of a double region scheme with an In-rich internal core and an In-poor external shell, in order to mimic the atomic scale phenomena such as In-Ga intermixing and In segregation during the growth and overgrowth with GaAs. The parameters of the proposed model are derived by reproducing the experimentally measured polarization data. Further understanding is developed by analyzing the strain fields which suggests that the two-composition model indeed results in lower strain energies than the commonly applied uniform composition model.