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Title: Energetics of intrinsic defects and their complexes in ZnO investigated by density functional calculations

Abstract

Formation energies of various intrinsic defects and defect complexes in ZnO have been calculated using a density-functional-theory-based pseudopotential all-electron method. The various defects considered are oxygen vacancy (V{sub O}), zinc vacancy (V{sub Zn}), oxygen at an interstitial site (O{sub i}), Zn at an interstitial site (Zn{sub i}), Zn at V{sub O} (Zn{sub O}), O at V{sub Zn}(O{sub Zn}), and an antisite pair (combination of the preceding two defects). In addition, defect complexes like (V{sub O}+Zn{sub i}) and Zn-vacancy clusters are studied. The Schokkty pair (V{sub O}+V{sub Zn}) and Frenkel pairs [(V{sub O}+O{sub i}) and (V{sub Zn}+Zn{sub i})] are considered theoretically for the first time. Upon comparing the formation energies of these defects, we find that V{sub O} would be the dominant intrinsic defect under both Zn-rich and O-rich conditions and it is a deep double donor. Both Zn{sub O} and Zn{sub i} are found to be shallow donors. The low formation energy of donor-type intrinsic defects could lead to difficulty in achieving p-type conductivity in ZnO. Defect complexes have charge transitions deep inside the band gap. The red, yellow, and green photoluminescence peaks of undoped samples can be assigned to some of the defect complexes considered. It is believed thatmore » the red luminescence originates from an electronic transition in V{sub O}, but we find that it can originate from the antisite Zn{sub O} defect. Charge density and electron-localization function analyses have been used to understand the effect of these defects on the ZnO lattice. The electronic structure of ZnO with intrinsic defects has been studied using density-of-states and electronic band structure plots. The acceptor levels introduced by V{sub Zn} are relatively localized, making it difficult to achieve p-type conductivity with sufficient hole mobility.« less

Authors:
; ;  [1]; ;  [2]; ;  [3]
  1. Center for Materials Science and Nanotechnology and Department of Chemistry, University of Oslo, Box 1033 Blindern, N-0315 Oslo (Norway)
  2. Center for Materials Science and Nanotechnology and Department of Physics, Physical Electronics, University of Oslo, Box 1048 Blindern, N-0316 Oslo (Norway)
  3. Laboratory of Physics, Helsinki University of Technology, P.O. Box 1100, F-02015 HUT (Finland)
Publication Date:
OSTI Identifier:
21538067
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 83; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevB.83.045206; (c) 2011 American Institute of Physics; Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; CHARGE DENSITY; COMPLEXES; COMPUTERIZED SIMULATION; CRYSTAL DEFECTS; DENSITY; DENSITY FUNCTIONAL METHOD; ELECTRONIC STRUCTURE; ELECTRONS; FORMATION HEAT; HOLE MOBILITY; INTERSTITIALS; PHOTOLUMINESCENCE; VACANCIES; ZINC; ZINC OXIDES; CALCULATION METHODS; CHALCOGENIDES; CRYSTAL STRUCTURE; ELEMENTARY PARTICLES; ELEMENTS; EMISSION; ENTHALPY; FERMIONS; LEPTONS; LUMINESCENCE; METALS; MOBILITY; OXIDES; OXYGEN COMPOUNDS; PHOTON EMISSION; PHYSICAL PROPERTIES; POINT DEFECTS; REACTION HEAT; SIMULATION; THERMODYNAMIC PROPERTIES; VARIATIONAL METHODS; ZINC COMPOUNDS

Citation Formats

Vidya, R, Ravindran, P, Fjellvaag, H, Svensson, B G, Monakhov, E, Ganchenkova, M, and Nieminen, R M. Energetics of intrinsic defects and their complexes in ZnO investigated by density functional calculations. United States: N. p., 2011. Web. doi:10.1103/PHYSREVB.83.045206.
Vidya, R, Ravindran, P, Fjellvaag, H, Svensson, B G, Monakhov, E, Ganchenkova, M, & Nieminen, R M. Energetics of intrinsic defects and their complexes in ZnO investigated by density functional calculations. United States. https://doi.org/10.1103/PHYSREVB.83.045206
Vidya, R, Ravindran, P, Fjellvaag, H, Svensson, B G, Monakhov, E, Ganchenkova, M, and Nieminen, R M. Sat . "Energetics of intrinsic defects and their complexes in ZnO investigated by density functional calculations". United States. https://doi.org/10.1103/PHYSREVB.83.045206.
@article{osti_21538067,
title = {Energetics of intrinsic defects and their complexes in ZnO investigated by density functional calculations},
author = {Vidya, R and Ravindran, P and Fjellvaag, H and Svensson, B G and Monakhov, E and Ganchenkova, M and Nieminen, R M},
abstractNote = {Formation energies of various intrinsic defects and defect complexes in ZnO have been calculated using a density-functional-theory-based pseudopotential all-electron method. The various defects considered are oxygen vacancy (V{sub O}), zinc vacancy (V{sub Zn}), oxygen at an interstitial site (O{sub i}), Zn at an interstitial site (Zn{sub i}), Zn at V{sub O} (Zn{sub O}), O at V{sub Zn}(O{sub Zn}), and an antisite pair (combination of the preceding two defects). In addition, defect complexes like (V{sub O}+Zn{sub i}) and Zn-vacancy clusters are studied. The Schokkty pair (V{sub O}+V{sub Zn}) and Frenkel pairs [(V{sub O}+O{sub i}) and (V{sub Zn}+Zn{sub i})] are considered theoretically for the first time. Upon comparing the formation energies of these defects, we find that V{sub O} would be the dominant intrinsic defect under both Zn-rich and O-rich conditions and it is a deep double donor. Both Zn{sub O} and Zn{sub i} are found to be shallow donors. The low formation energy of donor-type intrinsic defects could lead to difficulty in achieving p-type conductivity in ZnO. Defect complexes have charge transitions deep inside the band gap. The red, yellow, and green photoluminescence peaks of undoped samples can be assigned to some of the defect complexes considered. It is believed that the red luminescence originates from an electronic transition in V{sub O}, but we find that it can originate from the antisite Zn{sub O} defect. Charge density and electron-localization function analyses have been used to understand the effect of these defects on the ZnO lattice. The electronic structure of ZnO with intrinsic defects has been studied using density-of-states and electronic band structure plots. The acceptor levels introduced by V{sub Zn} are relatively localized, making it difficult to achieve p-type conductivity with sufficient hole mobility.},
doi = {10.1103/PHYSREVB.83.045206},
url = {https://www.osti.gov/biblio/21538067}, journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 4,
volume = 83,
place = {United States},
year = {2011},
month = {1}
}