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Title: Effect of catalyst diameter on vapour-liquid-solid growth of GaAs nanowires

GaAs nanowires were grown on (111)B GaAs substrates using the vapour-liquid-solid mechanism. The Au/Pt nanodots used to catalyse wire growth were defined lithographically and had varying diameter and separation. An in-depth statistical analysis of the resulting nanowires, which had a cone-like shape, was carried out. This revealed that there were two categories of nanowire present, with differing height and tapering angle. The bimodal nature of wire shape was found to depend critically on the diameter of the Au-Ga droplet atop the nanowire. Transmission electron microscopy analysis also revealed that the density of stacking faults in the wires varied considerably between the two categories of wire. It is believed that the cause of the distinction in terms of shape and crystal structure is related to the contact angle between the droplet and the solid-liquid interface. The dependency of droplet diameter on contact angle is likely related to line-tension, which is a correction to Young's equation for the contact angle of a droplet upon a surface. The fact that contact angle may influence resulting wire structure and shape has important implications for the planning of growth conditions and the preparation of wires for use in proposed devices.
Authors:
;  [1] ; ; ; ;  [2] ;  [3] ; ; ; ;  [4]
  1. CRANN, School of Physics, Trinity College, the University of Dublin, Dublin D2 (Ireland)
  2. Institute of Physics, Polish Academy of Sciences, Warsaw 02-668 (Poland)
  3. Notre Dame Integrated Imaging Facility (NDIIF), University of Notre Dame, Notre Dame, Indiana 46556 (United States)
  4. Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
Publication Date:
OSTI Identifier:
22314594
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CATALYSTS; DENSITY; DEPTH; DROPLETS; GALLIUM ARSENIDES; LIQUIDS; QUANTUM DOTS; QUANTUM WIRES; SHAPE; STACKING FAULTS; SUBSTRATES; SURFACES; TRANSMISSION ELECTRON MICROSCOPY; VAPORS