Microstructure of Mg doped GaNAs alloys

Z. Liliental-Weber*, Roberto dos Reis, S. V. Novikov, K. M. Yu, A. X. Levander, O. D. Dubon, J. Wu, W. Walukiewicz, C. T. Foxon

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Transmission Electron Microscopy of Mg doped GaN1-xAsx samples, grown by MBE at low temperatures, show substantial structural changes for samples that are semi-insulating and those with high or low conductivity. The conductive samples show p-type conductivity as evidence from the positive thermopower values. All the Mg doped samples show phase segregation: cubic GaAs and GaN grains (a mixture of cubic and some hexagonal) phases within an amorphous matrix. The best conductive samples show cubic GaAs grains with high density of stacking faults embedded into an amorphous matrix. The samples that are less conductive have lower ratio of the amorphous to the crystalline phase of the samples and much lower density of stacking faults. Higher Mg concentration is expected in the amorphous parts of the samples The semi-insulating samples that have either low Mg concentration or low As show grains of GaAs and GaN attached to each other with no evidence of the amorphous phase between them. There are no SFs in these grains. It is possible that the presence of the GaN between the GaAs grains lead to semi-insulating material properties since p-type doping of GaN is more difficult.

Original languageEnglish (US)
Pages (from-to)453-456
Number of pages4
JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
Volume10
Issue number3
DOIs
StatePublished - Mar 2013

Keywords

  • Amorphous materials
  • Conductivity
  • Nitride semiconductors
  • P-doping
  • Planar defect
  • TEM

ASJC Scopus subject areas

  • Condensed Matter Physics

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