Interface dynamics and crystal phase switching in GaAs nanowires

Research output: Contribution to journalArticle

Abstract

Controlled formation of non-equilibrium crystal structures is one of the most important challenges in crystal growth. Catalytically grown nanowires are ideal systems for studying the fundamental physics of phase selection, and could lead to new electronic applications based on the engineering of crystal phases. Here we image gallium arsenide (GaAs) nanowires during growth as they switch between phases as a result of varying growth conditions. We find clear differences between the growth dynamics of the phases, including differences in interface morphology, step flow and catalyst geometry. We explain these differences, and the phase selection, using a model that relates the catalyst volume, the contact angle at the trijunction (the point at which solid, liquid and vapour meet) and the nucleation site of each new layer of GaAs. This model allows us to predict the conditions under which each phase should be observed, and use these predictions to design GaAs heterostructures. These results could apply to phase selection in other nanowire systems.

Details

Authors
Organisations
External organisations
  • IBM Thomas J. Watson Research Center
  • University of Cambridge
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Nano Technology
Original languageEnglish
Pages (from-to)317-322
Number of pages6
JournalNature
Volume531
Issue number7594
Publication statusPublished - 2016 Mar 16
Publication categoryResearch
Peer-reviewedYes