Metamorphic GaAs/GaAsBi Heterostructured Nanowires

Fumitaro Ishikawa, Yoshihiko Akamatsu, Kentaro Watanabe, Fumihiko Uesugi, Shunsuke Asahina, Uwe Jahn, Satoshi Shimomura

Research output: Contribution to journalArticlepeer-review

21 Citations (Scopus)

Abstract

GaAs/GaAsBi coaxial multishell nanowires were grown by molecular beam epitaxy. Introducing Bi results in a characteristic nanowire surface morphology with strong roughening. Elemental mappings clearly show the formation of the GaAsBi shell with inhomogeneous Bi distributions within the layer surrounded by the outermost GaAs, having a strong structural disorder at the wire surface. The nanowire exhibits a predominantly ZB structure from the bottom to the middle part. The polytipic WZ structure creates denser twin defects in the upper part than in the bottom and middle parts of the nanowire. We observe room temperature cathodoluminescence from the GaAsBi nanowires with a broad spectral line shape between 1.1 and 1.5 eV, accompanied by multiple peaks. A distinct energy peak at 1.24 eV agrees well with the energy of the reduced GaAsBi alloy band gap by the introduction of 2% Bi. The existence of localized states energetically and spatially dispersed throughout the NW are indicated from the low temperature cathodoluminescence spectra and images, resulting in the observed luminescence spectra characterized by large line widths at low temperatures as well as by the appearance of multiple peaks at high temperatures and for high excitation powers.

Original languageEnglish
Pages (from-to)7265-7272
Number of pages8
JournalNano Letters
Volume15
Issue number11
DOIs
Publication statusPublished - 2015 Nov 11
Externally publishedYes

Keywords

  • GaAs
  • GaAsBi
  • Semiconductor nanowires
  • luminescence
  • roughening

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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