Electronic structure and phase stability of oxide semiconductors: Performance of dielectric-dependent hybrid functional DFT, benchmarked against $GW$ band structure calculations and experiments

摘要

We investigate band gaps, equilibrium structures, and phase stabilities ofseveral bulk polymorphs of wide-gap oxide semiconductors ZnO, TiO2,ZrO2, andWO3. We are particularly concerned with assessing the performance of hybridfunctionals built with the fraction of Hartree-Fock exact exchange obtainedfrom the computed electronic dielectric constant of the material. We providecomparison with more standard density-functional theory and GW methods. Wefinally analyze the chemical reduction of TiO2 into Ti2O3, involving a changein oxide stoichiometry. We show that the dielectric-dependent hybrid functionalis generally good at reproducing both ground-state (lattice constants, phasestability sequences, and reaction energies) and excited-state (photoemissiongaps) properties within a single, fully ab initio framework.