Wurtzite-to amorphous-to cubic phase transition of GaN1-x Asx alloys with increasing As content

Z. Liliental-Weber*, Roberto dos Reis, A. Levander, K. M. Yu, W. Walukiewicz, S. V. Novikov, C. T. Foxon

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

This paper describes Transmission Electron Microscopy studies of the structural changes of GaN1-xAsx alloys grown by Molecular Beam Epitaxy at low temperatures on Al2O3 substrate. We found that by lowering the growth temperature increasing amount of As can be incorporated in GaN 1-xAsx forming a single phase alloy. For the low As content a columnar growth of wurtzite structure is observed but for increasing As in the range of 0.17<x>0.75 the layer becomes amorphous. Increase in Ga flux at low growth temperature (about 200°C) leads to columnar alloys with As content >75% with a cubic structure. In addition to the structural changes monotonic change of the band gap is also observed with the As content in the alloy. The amorphous alloy is stable up to annealing at temperatures not higher than 600°C. Annealing at higher temperature leads to phase separation of GaAs:N and GaN:As confirmed by Z-contrast electron microscopy.

Original languageEnglish (US)
Title of host publicationElectron Microscopy XIV
PublisherTrans Tech Publications Ltd
Pages74-77
Number of pages4
ISBN (Print)9783037853818
DOIs
StatePublished - 2012
Event14th International Conference on Electron Microscopy, EM 2011 - Wisla, Poland
Duration: Jun 26 2011Jun 30 2011

Publication series

NameSolid State Phenomena
Volume186
ISSN (Print)1012-0394

Conference

Conference14th International Conference on Electron Microscopy, EM 2011
Country/TerritoryPoland
CityWisla
Period6/26/116/30/11

Keywords

  • Amorphous
  • Bandgap
  • Columnar structure
  • Cubic
  • GaNAs
  • Phase transformation
  • Wurtzite

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Materials Science(all)
  • Condensed Matter Physics

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