Atomistic and continuum modeling of a zincblende quantum dot heterostructure

TL;DR

This paper presents a multiscale modeling approach combining atomistic strain calculations with continuum k.p Hamiltonian methods to efficiently and accurately simulate electronic states in zincblende quantum dot heterostructures.

Contribution

It introduces an integrated multi-scale simulation method that significantly reduces computational resources while maintaining accuracy in quantum dot electronic structure predictions.

Findings

Multi-scale approach yields six-fold faster simulations.

Optical transition wavelengths within 7% of tight-binding results.

Multi-scale method accurately captures strain effects on electronic states.

Abstract

A multiscale approach was adopted for the calculation of confined states in self-assembled semiconductor quantum dots (QDs). While results close to experimental data have been obtained with a combination of atomistic strain and tight-binding (TB) electronic structure description for the confined quantum states in the QD, the TB calculation requires substantial computational resources. To alleviate this problem an integrated approach was adopted to compute the energy states from a continuum 8-band k.p Hamiltonian under the influence of an atomistic strain field. Such multi-scale simulations yield a roughly six-fold faster simulation. Atomic-resolution strain is added to the k.p Hamiltonian through interpolation onto a coarser continuum grid. Sufficient numerical accuracy is obtained by the multi-scale approach. Optical transition wavelengths are within 7% of the corresponding TB results with a proper splitting of p-type sub-bands. The systematically lower emission wavelengths in k.p are attributable to an underestimation of the coupling between the conduction and valence bands.