Suppression of alloy fluctuations in GaAs-AlGaAs core-shell nanowires

Bernhard Loitsch, Nari Jeon, Markus Döblinger, Julia Winnerl, Eric Parzinger, Sonja Matich, Ursula Wurstbauer, Hubert Riedl, Gerhard Abstreiter, Jonathan J. Finley, Lincoln James Lauhon, Gregor Koblmüller

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Probing localized alloy fluctuations and controlling them by growth kinetics have been relatively limited so far in nanoscale structures such as semiconductor nanowires (NWs). Here, we demonstrate the tuning of alloy fluctuations in molecular beam epitaxially grown GaAs-AlGaAs core-shell NWs by modifications of shell growth temperature, as investigated by correlated micro-photoluminescence, scanning transmission electron microscopy, and atom probe tomography. By reducing the shell growth temperature from T > 600 °C to below 400 °C, we find a strong reduction in alloy fluctuation mediated sharp-line luminescence, concurrent with a decrease in the non-randomness of the alloy distribution in the AlGaAs shell. This trend is further characterized by a change in the alloy compositional structure from unintentional quasi-superlattices of Ga- and Al-rich AlGaAs layers at high T to a nearly homogeneous random alloy distribution at low T.

Original languageEnglish (US)
Article number093105
JournalApplied Physics Letters
Volume109
Issue number9
DOIs
StatePublished - Aug 29 2016

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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