Thickness dependence of the strain, band gap and transport properties of epitaxial In2O3 thin films grown on Y-stabilised ZrO 2(111)

K. H.L. Zhang, V. K. Lazarov, T. D. Veal, F. E. Oropeza, C. F. McConville, R. G. Egdell, A. Walsh

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Epitaxial films of In2O3 have been grown on Y-stabilised ZrO2(111) substrates by molecular beam epitaxy over a range of thicknesses between 35 and 420nm. The thinnest films are strained, but display a 'cross-hatch' morphology associated with a network of misfit dislocations which allow partial accommodation of the lattice mismatch. With increasing thickness a 'dewetting' process occurs and the films break up into micron sized mesas, which coalesce into continuous films at the highest coverages. The changes in morphology are accompanied by a progressive release of strain and an increase in carrier mobility to a maximum value of 73cm 2V- 1s- 1. The optical band gap in strained ultrathin films is found to be smaller than for thicker films. Modelling of the system, using a combination of classical pair-wise potentials and ab initio density functional theory, provides a microscopic description of the elastic contributions to the strained epitaxial growth, as well as the electronic effects that give rise to the observed band gap changes. The band gap increase induced by the uniaxial compression is offset by the band gap reduction associated with the epitaxial tensile strain.

Original languageEnglish
Article number334211
JournalJournal of Physics Condensed Matter
Volume23
Issue number33
DOIs
Publication statusPublished - 2011 Aug 24

Fingerprint

Electron transport properties
Epitaxial films
Energy gap
transport properties
Thin films
thin films
Hatches
Lattice mismatch
Ultrathin films
Tensile strain
Carrier mobility
Optical band gaps
hatches
Dislocations (crystals)
Epitaxial growth
Thick films
Molecular beam epitaxy
Density functional theory
accommodation
mesas

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Zhang, K. H.L. ; Lazarov, V. K. ; Veal, T. D. ; Oropeza, F. E. ; McConville, C. F. ; Egdell, R. G. ; Walsh, A. / Thickness dependence of the strain, band gap and transport properties of epitaxial In2O3 thin films grown on Y-stabilised ZrO 2(111). In: Journal of Physics Condensed Matter. 2011 ; Vol. 23, No. 33.
@article{a668801eb425401f97586ec530c5ffa8,
title = "Thickness dependence of the strain, band gap and transport properties of epitaxial In2O3 thin films grown on Y-stabilised ZrO 2(111)",
abstract = "Epitaxial films of In2O3 have been grown on Y-stabilised ZrO2(111) substrates by molecular beam epitaxy over a range of thicknesses between 35 and 420nm. The thinnest films are strained, but display a 'cross-hatch' morphology associated with a network of misfit dislocations which allow partial accommodation of the lattice mismatch. With increasing thickness a 'dewetting' process occurs and the films break up into micron sized mesas, which coalesce into continuous films at the highest coverages. The changes in morphology are accompanied by a progressive release of strain and an increase in carrier mobility to a maximum value of 73cm 2V- 1s- 1. The optical band gap in strained ultrathin films is found to be smaller than for thicker films. Modelling of the system, using a combination of classical pair-wise potentials and ab initio density functional theory, provides a microscopic description of the elastic contributions to the strained epitaxial growth, as well as the electronic effects that give rise to the observed band gap changes. The band gap increase induced by the uniaxial compression is offset by the band gap reduction associated with the epitaxial tensile strain.",
author = "Zhang, {K. H.L.} and Lazarov, {V. K.} and Veal, {T. D.} and Oropeza, {F. E.} and McConville, {C. F.} and Egdell, {R. G.} and A. Walsh",
year = "2011",
month = "8",
day = "24",
doi = "10.1088/0953-8984/23/33/334211",
language = "English",
volume = "23",
journal = "Journal of Physics Condensed Matter",
issn = "0953-8984",
publisher = "IOP Publishing Ltd.",
number = "33",

}

Thickness dependence of the strain, band gap and transport properties of epitaxial In2O3 thin films grown on Y-stabilised ZrO 2(111). / Zhang, K. H.L.; Lazarov, V. K.; Veal, T. D.; Oropeza, F. E.; McConville, C. F.; Egdell, R. G.; Walsh, A.

In: Journal of Physics Condensed Matter, Vol. 23, No. 33, 334211, 24.08.2011.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Thickness dependence of the strain, band gap and transport properties of epitaxial In2O3 thin films grown on Y-stabilised ZrO 2(111)

AU - Zhang, K. H.L.

AU - Lazarov, V. K.

AU - Veal, T. D.

AU - Oropeza, F. E.

AU - McConville, C. F.

AU - Egdell, R. G.

AU - Walsh, A.

PY - 2011/8/24

Y1 - 2011/8/24

N2 - Epitaxial films of In2O3 have been grown on Y-stabilised ZrO2(111) substrates by molecular beam epitaxy over a range of thicknesses between 35 and 420nm. The thinnest films are strained, but display a 'cross-hatch' morphology associated with a network of misfit dislocations which allow partial accommodation of the lattice mismatch. With increasing thickness a 'dewetting' process occurs and the films break up into micron sized mesas, which coalesce into continuous films at the highest coverages. The changes in morphology are accompanied by a progressive release of strain and an increase in carrier mobility to a maximum value of 73cm 2V- 1s- 1. The optical band gap in strained ultrathin films is found to be smaller than for thicker films. Modelling of the system, using a combination of classical pair-wise potentials and ab initio density functional theory, provides a microscopic description of the elastic contributions to the strained epitaxial growth, as well as the electronic effects that give rise to the observed band gap changes. The band gap increase induced by the uniaxial compression is offset by the band gap reduction associated with the epitaxial tensile strain.

AB - Epitaxial films of In2O3 have been grown on Y-stabilised ZrO2(111) substrates by molecular beam epitaxy over a range of thicknesses between 35 and 420nm. The thinnest films are strained, but display a 'cross-hatch' morphology associated with a network of misfit dislocations which allow partial accommodation of the lattice mismatch. With increasing thickness a 'dewetting' process occurs and the films break up into micron sized mesas, which coalesce into continuous films at the highest coverages. The changes in morphology are accompanied by a progressive release of strain and an increase in carrier mobility to a maximum value of 73cm 2V- 1s- 1. The optical band gap in strained ultrathin films is found to be smaller than for thicker films. Modelling of the system, using a combination of classical pair-wise potentials and ab initio density functional theory, provides a microscopic description of the elastic contributions to the strained epitaxial growth, as well as the electronic effects that give rise to the observed band gap changes. The band gap increase induced by the uniaxial compression is offset by the band gap reduction associated with the epitaxial tensile strain.

UR - http://www.scopus.com/inward/record.url?scp=80051931748&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80051931748&partnerID=8YFLogxK

U2 - 10.1088/0953-8984/23/33/334211

DO - 10.1088/0953-8984/23/33/334211

M3 - Article

C2 - 21813945

AN - SCOPUS:80051931748

VL - 23

JO - Journal of Physics Condensed Matter

JF - Journal of Physics Condensed Matter

SN - 0953-8984

IS - 33

M1 - 334211

ER -