Electronic structure and phase stability of oxide semiconductors: Performance of dielectric-dependent hybrid functional DFT, benchmarked against<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>G</mml:mi><mml:mi>W</mml:mi></mml:mrow></mml:math>band structure calculations and experiments

Abstract

We investigate band gaps, equilibrium structures, and phase stabilities of several bulk polymorphs of wide-gap oxide semiconductors ZnO, ${\mathrm{TiO}}_{2},\phantom{\rule{0.16em}{0ex}}{\mathrm{ZrO}}_{2}$, and ${\mathrm{WO}}_{3}$. We are particularly concerned with assessing the performance of hybrid functionals built with the fraction of Hartree-Fock exact exchange obtained from the computed electronic dielectric constant of the material. We provide comparison with more standard density-functional theory and $\mathit{GW}$ methods. We finally analyze the chemical reduction of ${\mathrm{TiO}}_{2}$ into ${\mathrm{Ti}}_{2}{\mathrm{O}}_{3}$, involving a change in oxide stoichiometry. We show that the dielectric-dependent hybrid functional is generally good at reproducing both ground-state (lattice constants, phase stability sequences, and reaction energies) and excited-state (photoemission gaps) properties within a single, fully ab initio framework.