First principles prediction of structural and electronic properties of TlxIn(1-x)N alloy

TL;DR

This study uses first-principles calculations to explore the structural and electronic properties of TlxIn(1-x)N alloys, revealing potential for optoelectronic applications and topological insulator behavior at certain compositions.

Contribution

It provides the first theoretical analysis of TlxIn(1-x)N alloys' electronic structure, highlighting their band-gap behavior and spin-orbit effects across different Tl contents.

Findings

Band-gap decreases linearly with Tl content up to 25%.

Split-off energy at Gamma point is comparable to the band-gap at 5% Tl.

TlN exhibits properties characteristic of topological insulators.

Abstract

Structural and electronic properties of zinc blende TlxIn(1-x)N alloy have been evaluated from first principles. The band structures have been obtained within the density functional theory (DFT), the modified Becke-Johnson (MBJLDA) approach for the exchange-correlation potential, and fully relativistic pseudopotentials. The calculated band-gap dependence on Tl content in this hypothetical alloy exhibits a linear behaviour up to the 25 % of thalium content where its values become close to zero. In turn, the split-off energy at the Gamma point of the Brillouin zone, related to the spin-orbit coupling, is predicted to be comparable in value with the band-gap for relatively low thalium contents of about 5 %. These findings suggest TlxIn(1-x)N alloy as a promising material for optoelectronic applications. Furthermore, the band structure of TlN reveals some specific properties exhibited by topological insulators.