We investigate the behavior of oxygen vacancies in three different metal-oxide semiconductors (rutile and anatase TiO2, monoclinic WO3, and tetragonal ZrO2) using a recently proposed hybrid density-functional method in which the fraction of exact exchange is material-dependent but obtained ab initio in a self-consistent scheme. In particular, we calculate charge-transition levels relative to the oxygen-vacancy defect and compare computed optical and thermal excitation/emission energies with the available experimental results, shedding light on the underlying excitation mechanisms and related materials properties. We find that this novel approach is able to reproduce not only ground-state properties and band structures of perfect bulk oxide materials but also provides results consistent with the optical and electrical behavior observed in the corresponding substoichiometric defective systems.

Defect calculations in semiconductors through a dielectric-dependent hybrid DFT functional : the case of oxygen vacancies in metal oxides / M. Gerosa, C.E. Bottani, L. Caramella, G. Onida, C. Di Valentin, G. Pacchioni. - In: THE JOURNAL OF CHEMICAL PHYSICS. - ISSN 0021-9606. - 143:13(2015 Oct 07), pp. 134702.1-134702.9. [10.1063/1.4931805]

Defect calculations in semiconductors through a dielectric-dependent hybrid DFT functional : the case of oxygen vacancies in metal oxides

L. Caramella;G. Onida;
2015

Abstract

We investigate the behavior of oxygen vacancies in three different metal-oxide semiconductors (rutile and anatase TiO2, monoclinic WO3, and tetragonal ZrO2) using a recently proposed hybrid density-functional method in which the fraction of exact exchange is material-dependent but obtained ab initio in a self-consistent scheme. In particular, we calculate charge-transition levels relative to the oxygen-vacancy defect and compare computed optical and thermal excitation/emission energies with the available experimental results, shedding light on the underlying excitation mechanisms and related materials properties. We find that this novel approach is able to reproduce not only ground-state properties and band structures of perfect bulk oxide materials but also provides results consistent with the optical and electrical behavior observed in the corresponding substoichiometric defective systems.
DFT; ab-initio; Defetcs; Oxydes; hybrid functionals
Settore FIS/03 - Fisica della Materia
Settore CHIM/02 - Chimica Fisica
7-ott-2015
Article (author)
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/330501
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