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Title: A polarity-driven nanometric luminescence asymmetry in AlN/GaN heterostructures

Group III Nitrides nanowires are well suited materials for the design of light emitting devices. The internal electric field created by spontaneaous and piezoelectric polarizations in these materials poses some difficulties, but also possible solutions, towards this goal. Here, we report on the high spatial asymmetry of the cathodoluminescence intensity across a GaN quantum well embedded in an AlN nanowire, when a 60 keV, 1 nm wide electron beam is scanned over this heterostructure. This asymmetry is remarkable between positions at different sides of the quantum well. We interpret this asymmetry as originating from the different drift directions of carriers due to the internal electric field. This interpretation is corroborated by the direct determination of the polarity with convergent beam electron diffraction. A precise knowledge of hole mobility and diffusion coefficients would allow an estimate of the electric field in the AlN segment of the nanowire.
Authors:
; ; ;  [1] ; ; ;  [2]
  1. Laboratoire de Physique des Solides, Université Paris-Sud, CNRS-UMR 8502, Orsay 91405 (France)
  2. CEA-CNRS Group Nanophysique et Semiconducteurs, Institut Neel/CNRS-Université J. Fourier and CEA Grenoble, INAC, SP2M, 17 rue des Martyrs, 38 054 Grenoble (France)
Publication Date:
OSTI Identifier:
22351130
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 14; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; ALUMINIUM NITRIDES; ASYMMETRY; CARRIERS; CATHODOLUMINESCENCE; DIFFUSION; ELECTRIC FIELDS; ELECTRON BEAMS; ELECTRON DIFFRACTION; EQUIPMENT; GALLIUM NITRIDES; HOLE MOBILITY; NANOWIRES; PIEZOELECTRICITY; POLARIZATION; QUANTUM WELLS; QUANTUM WIRES