We investigate band gaps, equilibrium structures, and phase stabilities of several bulk polymorphs of wide-gap oxide semiconductors ZnO, TiO2,ZrO2, and WO3. 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 GW methods. We finally analyze the chemical reduction of TiO2 into Ti2O3, 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.
|Titolo:||Electronic structure and phase stability of oxide semiconductors: performance of dielectric-dependent hybrid functional DFT, benchmarked against GW band structure calculations and experiments|
|Parole Chiave:||space Gaussian pseudopotentials; WO3 thin-films; AB-initio; tungsten trioxide; quasi-particle; hartree-fock; anatase TIO2; density functionals; hydrogen-production; optical-properties|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||2015|
|Digital Object Identifier (DOI):||10.1103/PhysRevB.91.155201|
|Appare nelle tipologie:||01 - Articolo su periodico|