Effects of atomic clustering on the optical properties of III-V alloys

TL;DR

This study investigates how atomic clustering influences the optical properties of III-V alloys, revealing that clustering can significantly reduce the band gap and potentially convert indirect to direct gap materials.

Contribution

It provides a detailed analysis of the impact of short-range atomic order on the optical properties of specific III-V alloys using self-consistent electronic structure calculations.

Findings

Clustering reduces the band gap by up to 100 meV.

Strong clustering can turn AlGaAs into a direct gap material.

Atomic order significantly affects optical properties.

Abstract

Self-consistent electronic structure calculations together with a structural model are used to study the effect of short-range atomic order on the optical properties of otherwise random Al(0.5)Ga(0.5)As, Ga(0.5)In(0.5)P, and Al(0.5)In(0.5)As alloys. We find that clustering can reduce the direct band gap of these alloys by as much as 100 meV. Furthermore, sufficiently strong clustering is predicted to transform Al(0.5)Ga(0.5)As into a direct gap material.