Strain induced variations in transport and optical properties of SrVO$_3$: a DFT+U study

TL;DR

This study uses DFT+U calculations to explore how strain affects the electronic, optical, and transport properties of SrVO$_3$, revealing how tensile and compressive strains can tune its conductivity and transparency for optoelectronic applications.

Contribution

The paper provides a detailed first-principles analysis of strain effects on SrVO$_3$, highlighting mechanisms to optimize its properties as a transparent conductor.

Findings

Tensile strain reduces conductivity by narrowing the d-band and lifting orbital degeneracy.

Compressive strain enhances metallicity by widening the d-band and increasing carrier concentration.

Strain tuning can modulate the plasma frequency and optical transparency window.

Abstract

First-principles calculations based on density functional theory + Hubbard U (DFT+U) approach have been carried out to study the strain induced variations in the optical and transport properties of the correlated perovskite SrVO$_3$. By virtue of its conductivity, high carrier mobility and optical transparency, SrVO$_3$ can be used as a potential replacement of indium tin oxide (ITO) as a transparent conductor. As strain tuning is an effective way to tune the electron-electron correlations in correlated oxides, the epitaxial strain induced variations in V-3d bandwidth, band center shift and band splitting at high symmetry points (${\Gamma}$, R) in SrVO$_3$ are investigated. The alterations in resistivity, carrier concentration, Hall coefficient and plasma frequency with applied strain are also elucidated. Our calculations revealed that under tensile strain, the lifting of the threefold degeneracy of 3d-t$_{2g}$ orbital and d-band narrowing reinforces a relatively less conducting state thus limiting the $\omega_P$ to lower frequencies. On the contrary, in case of compressive strain the d-band widening predominates leading to an increase in carrier concentration and decrease in resistivity enhancing the metallic state. As a result, $\omega_P$ is increased to higher frequencies which decreases the optical transparency window. Hence, our results and findings clearly demonstrate the interdependence between the optical and transport properties, and provides a detailed mechanism to tune the optoelectronic properties of SrVO$_3$ for its applications as a transparent conducting oxide.