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Title: Oxygen defects in amorphous Al{sub 2}O{sub 3}: A hybrid functional study

Abstract

The electronic properties of the oxygen vacancy and interstitial in amorphous Al{sub 2}O{sub 3} are studied via ab initio molecular dynamics simulations and hybrid functional calculations. Our results indicate that these defects do not occur in amorphous Al{sub 2}O{sub 3}, due to structural rearrangements which assimilate the defect structure and cause a delocalization of the associated defect levels. The imbalance of oxygen leads to a nonstoichiometric compound in which the oxygen occurs in the form of O{sup 2–} ions. Intrinsic oxygen defects are found to be unable to trap excess electrons. For low Fermi energies, the formation of peroxy linkages is found to be favored leading to the capture of holes. The relative +2/0 defect levels occur at 2.5 eV from the valence band.

Authors:
; ;  [1]
  1. Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)
Publication Date:
OSTI Identifier:
22594312
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM OXIDES; CAPTURE; COMPUTERIZED SIMULATION; DEFECTS; ELECTRONS; FERMI LEVEL; HOLES; HYBRIDIZATION; MOLECULAR DYNAMICS METHOD; OXYGEN; OXYGEN IONS; VACANCIES; VALENCE

Citation Formats

Guo, Zhendong, E-mail: zhendong.guo@epfl.ch, Ambrosio, Francesco, and Pasquarello, Alfredo. Oxygen defects in amorphous Al{sub 2}O{sub 3}: A hybrid functional study. United States: N. p., 2016. Web. doi:10.1063/1.4961125.
Guo, Zhendong, E-mail: zhendong.guo@epfl.ch, Ambrosio, Francesco, & Pasquarello, Alfredo. Oxygen defects in amorphous Al{sub 2}O{sub 3}: A hybrid functional study. United States. doi:10.1063/1.4961125.
Guo, Zhendong, E-mail: zhendong.guo@epfl.ch, Ambrosio, Francesco, and Pasquarello, Alfredo. 2016. "Oxygen defects in amorphous Al{sub 2}O{sub 3}: A hybrid functional study". United States. doi:10.1063/1.4961125.
@article{osti_22594312,
title = {Oxygen defects in amorphous Al{sub 2}O{sub 3}: A hybrid functional study},
author = {Guo, Zhendong, E-mail: zhendong.guo@epfl.ch and Ambrosio, Francesco and Pasquarello, Alfredo},
abstractNote = {The electronic properties of the oxygen vacancy and interstitial in amorphous Al{sub 2}O{sub 3} are studied via ab initio molecular dynamics simulations and hybrid functional calculations. Our results indicate that these defects do not occur in amorphous Al{sub 2}O{sub 3}, due to structural rearrangements which assimilate the defect structure and cause a delocalization of the associated defect levels. The imbalance of oxygen leads to a nonstoichiometric compound in which the oxygen occurs in the form of O{sup 2–} ions. Intrinsic oxygen defects are found to be unable to trap excess electrons. For low Fermi energies, the formation of peroxy linkages is found to be favored leading to the capture of holes. The relative +2/0 defect levels occur at 2.5 eV from the valence band.},
doi = {10.1063/1.4961125},
journal = {Applied Physics Letters},
number = 6,
volume = 109,
place = {United States},
year = 2016,
month = 8
}