Energy levels of In_x Ga_(1-x) As/GaAs quantum dot laser with different sizes

TL;DR

This study investigates how the size of InGaAs/GaAs quantum dots influences strain, band edges, and energy levels, revealing size-dependent electronic properties relevant for quantum dot laser design.

Contribution

It provides a detailed analysis of size effects on strain, energy levels, and degeneracy in InGaAs/GaAs quantum dots, enhancing understanding for optoelectronic applications.

Findings

Larger QDs have lower recombination energies.

Strain is higher at interfaces and in smaller QDs.

Energy levels become more discrete with size variation.

Abstract

In this paper, we have studied the strain, bandedge, and energy levels of cubic InGaAs quantum dots (QDs) surrounded by GaAs. It is shown that overall strain value is larger in InGaAs-GaAs interfaces, and also in smaller QDs. Also, it is proved that conduction and valence band-edges and electron-hole levels are size dependent; larger QD sizes appeared to result in the lower recombination energies. Moreover, more number of energy levels separates from the continuum states of bulk GaAs and comes down into the QD separate levels. In addition, degeneracy of eigenvalues was found to be subjected to change by size variation. Our results coincide with former similar researches. Keywords: strain, bandedge, engineering energy levels, quantum dot size, QD laser