Electronic structure of oxygen vacancies in hafnium oxide

Abstract

The electronic structure of oxygen vacancies and polyvacancies in HfO2 was studied theoretically from the first-principles calculations and experimentally, by X-ray photoelectron spectroscopy. The electronic structure calculations of crystalline HfO2 were performed within the hybrid density functional theory. The experimental photoelectron spectra indicate that both nonstoichiometric chemistry and Ar-ion bombardment of hafnia films lead to the generation of the defect states at 3.0 eV above the valence band. According to the calculations, these defect states are attributed to the oxygen vacancies.