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First-principles study of intrinsic point defects in ZnO: Role of band structure, volume relaxation, and finite-size effects

Erhart, Paul and Albe, Karsten and Klein, Andreas (2006):
First-principles study of intrinsic point defects in ZnO: Role of band structure, volume relaxation, and finite-size effects.
In: Physical Review B, American Physical Society, pp. 205203-1, 73, (20), ISSN 1098-0121, [Online-Edition: http://dx.doi.org/10.1103/PhysRevB.73.205203],
[Article]

Abstract

Density-functional theory (DFT) calculations of intrinsic point defect properties in zinc oxide were performed in order to remedy the influence of finite-size effects and the improper description of the band structure. The generalized gradient approximation (GGA) with empirical self-interaction corrections (GGA+U) was applied to correct for the overestimation of covalency intrinsic to GGA-DFT calculations. Elastic as well as electrostatic image interactions were accounted for by application of extensive finite-size scaling and compensating charge corrections. Size-corrected formation enthalpies and volumes as well as their charge state dependence have been deduced. Our results partly confirm earlier calculations but reveal a larger number of transition levels: (1) For both the zinc interstitial as well as the oxygen vacancy, transition levels are close to the conduction band minimum. (2) The zinc vacancy shows a transition rather close to the valence band maximum and another one near the middle of the calculated band gap. (3) For the oxygen interstitials, transition levels occur both near the valence band maximum and the conduction band minimum.

Item Type: Article
Erschienen: 2006
Creators: Erhart, Paul and Albe, Karsten and Klein, Andreas
Title: First-principles study of intrinsic point defects in ZnO: Role of band structure, volume relaxation, and finite-size effects
Language: English
Abstract:

Density-functional theory (DFT) calculations of intrinsic point defect properties in zinc oxide were performed in order to remedy the influence of finite-size effects and the improper description of the band structure. The generalized gradient approximation (GGA) with empirical self-interaction corrections (GGA+U) was applied to correct for the overestimation of covalency intrinsic to GGA-DFT calculations. Elastic as well as electrostatic image interactions were accounted for by application of extensive finite-size scaling and compensating charge corrections. Size-corrected formation enthalpies and volumes as well as their charge state dependence have been deduced. Our results partly confirm earlier calculations but reveal a larger number of transition levels: (1) For both the zinc interstitial as well as the oxygen vacancy, transition levels are close to the conduction band minimum. (2) The zinc vacancy shows a transition rather close to the valence band maximum and another one near the middle of the calculated band gap. (3) For the oxygen interstitials, transition levels occur both near the valence band maximum and the conduction band minimum.

Journal or Publication Title: Physical Review B
Volume: 73
Number: 20
Publisher: American Physical Society
Divisions: 11 Department of Materials and Earth Sciences > Material Science > Materials Modelling
11 Department of Materials and Earth Sciences > Material Science > Surface Science
Zentrale Einrichtungen
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > C - Modelling
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > C - Modelling > Subproject C2: Atomistic computer simulations of defects and their mobility in metal oxides
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > D - Component properties
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > D - Component properties > Subproject D3: Function and fatigue of oxide electrodes in organic light emitting diodes
11 Department of Materials and Earth Sciences > Material Science
11 Department of Materials and Earth Sciences
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres
DFG-Collaborative Research Centres (incl. Transregio)
Date Deposited: 16 Aug 2011 13:27
Official URL: http://dx.doi.org/10.1103/PhysRevB.73.205203
Additional Information:

SFB 595 Cooperation C2, D3

Identification Number: doi:10.1103/PhysRevB.73.205203
Funders: We acknowledge financial support through the Sonderforschungsbereich 595 “Fatigue in functional materials” of the Deutsche Forschungsgemeinschaft.
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