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Title: Long exciton lifetimes in stacking-fault-free wurtzite GaAs nanowires

We present a combined photoluminescence and transmission electron microscopy study of single GaAs nanowires. Each wire was characterized both in microscopy and spectroscopy, allowing a direct correlation of the optical and the structural properties. By tuning the growth parameters, the nanowire crystal structure is optimized from a highly mixed zincblende–wurtzite structure to pure wurtzite. We find the latter one to be stacking-fault-free over nanowire lengths up to 4.1 μm. We observe the emission of purely wurtzite nanowires to occur only with polarization directions perpendicular to the wurtzite c{sup ^}-axis, as expected from the hexagonal unit cell symmetry. The free exciton recombination energy in the wurtzite structure is 1.518 eV at 5 K with a narrow linewidth of 4 meV. Most notably, these pure wurtzite nanowires display long carrier recombination lifetimes of up to 11.2 ns, exceeding reported lifetimes in bulk GaAs and state-of-the-art 2D GaAs/AlGaAs heterostructures.
Authors:
; ; ; ; ; ; ; ;  [1]
  1. Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93040 Regensburg (Germany)
Publication Date:
OSTI Identifier:
22402408
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 22; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM ARSENIDES; CARRIER LIFETIME; CHARGE CARRIERS; GALLIUM ARSENIDES; NANOWIRES; PHOTOLUMINESCENCE; RECOMBINATION; SPECTROSCOPY; STACKING FAULTS; TRANSMISSION ELECTRON MICROSCOPY; ZINC SULFIDES