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Title: Atomistic simulation of Er irradiation induced defects in GaN nanowires

Classical molecular dynamics simulation was used to irradiate a GaN nanowire with rear-earth erbium (Er). Ten cumulative irradiations were done using an ion energy of 37.5 keV on a 10 × 10 nm²surface area which corresponds to a fluence of 1 × 10¹³ cm⁻². We studied the location and types of defects produced in the irradiation. Er implantation leads to a net positive (expansion) strain in the nanowire and especially at the top region a clear expansion has been observed in the lateral and axial directions. The lattice expansion is due to the hydrostatic strain imposed by a large number of radiation induced defects at the top of the NW. Due to the large surface-to-volume ratio, most of the defects were concentrated at the surface region, which suggests that the experimentally observed yellow luminescence (YL) in ion implanted GaN NWs arises from surface defects. We observed big clusters of point defects and vacancy clusters which are correlated with stable lattice strain and the YL band, respectively.
Authors:
; ; ;  [1] ;  [2]
  1. Department of Physics, University of Helsinki, P.O. Box 64, FIN-00014 (Finland)
  2. Technische Universität Darmstadt, 64287 Darmstadt (Germany)
Publication Date:
OSTI Identifier:
22305722
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 12; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; DEFECTS; ERBIUM IONS; EXPANSION; GALLIUM NITRIDES; IRRADIATION; KEV RANGE; LUMINESCENCE; MOLECULAR DYNAMICS METHOD; NANOWIRES; QUANTUM WIRES; SIMULATION; STRAINS; SURFACE AREA; SURFACES; VACANCIES