Accurate Ab-initio Predictions of III-V Direct-Indirect Band Gap Crossovers

TL;DR

This paper demonstrates that hybrid functional calculations accurately predict the compositional dependence of electronic band structures and the direct-indirect band gap crossovers in various III-V alloys, improving upon standard DFT methods.

Contribution

The study shows that HSE hybrid functional accurately reproduces experimental band gaps and crossover points, advancing predictive capabilities for III-V alloy electronic properties.

Findings

HSE functional matches experimental band gaps

Accurately predicts direct-indirect band gap crossovers

Improves reliability of ab-initio predictions for III-V alloys

Abstract

We report the compositional dependence of the electronic band structure for a range of III-V alloys. Density functional theory with the PBE functional is insufficient to mimic the electronic gap energies at different symmetry points of the Brillouin zone. The HSE hybrid functional with screened exchange accurately reproduces the experimental band gaps and, more importantly, the alloy concentration of the direct-indirect gap crossovers for the III-V alloys studied here: AlGaAs, InAlAs, AlInP, InGaP, and GaAsP.