Compositional bowing of band energies and their deformation potentials in strained InGaAs ternary alloys: a first-principles study

TL;DR

This study uses first-principles calculations to reveal significant compositional bowing in the band energies and deformation potentials of strained InGaAs alloys, showing the effect's insensitivity to computational models.

Contribution

It demonstrates the non-negligible bowing of band energies and deformation potentials in InGaAs alloys and shows this effect is consistent across different computational approaches.

Findings

Band energies exhibit compositional bowing in strained InGaAs.

Deformation potentials also show bowing effects.

The bowing is primarily influenced by In cations.

Abstract

Using first-principles calculations, we show that the conduction and valence band energies and their deformation potentials exhibit a non-negligible compositional bowing in strained ternary semiconductor alloys such as InGaAs. The electronic structure of these compounds has been calculated within the framework of local density approximation and hybrid functional approach for large cubic supercells and special quasi-random structures, which represent two kinds of model structures for random alloys. We find that the predicted bowing effect for the band energy deformation potentials is rather insensitive to the choice of the functional and alloy structural model. The direction of bowing is determined by In cations that give a stronger contribution to the formation of the In$_{x}$Ga$_{1-x}$As valence band states with $x\gtrsim 0.5$, compared to Ga cations.