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Optical and structural properties of dislocations in InGaN

Accepted version
Peer-reviewed

Type

Article

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Abstract

jats:pThreading dislocations in thick layers of InxGa1−xN (5% &lt; x &lt; 15%) have been investigated by means of cathodoluminescence, time-resolved cathodoluminescence, and molecular dynamics. We show that indium atoms segregate near dislocations in all the samples. This promotes the formation of In-N-In chains and atomic condensates, which localize carriers and hinder nonradiative recombination at dislocations. We note, however, that the dark halo surrounding the dislocations in the cathodoluminescence image becomes increasingly pronounced as the indium fraction of the sample increases. Using transmission electron microscopy, we attribute the dark halo to a region of lower indium content formed below the facet of the V-shaped pit that terminates the dislocation in low composition samples (x &lt; 12%). For x &gt; 12%, the facets of the V-defect featured dislocation bundles instead of the low indium fraction region. In this sample, the origin of the dark halo may relate to a compound effect of the dislocation bundles, of a variation of surface potential, and perhaps, of an increase in carrier diffusion length.</jats:p>

Description

Keywords

III-Nitrides, InGaN, Dislcoation, Cathodoluminescence

Journal Title

Journal of Applied Physics

Conference Name

Journal ISSN

0021-8979
1089-7550

Volume Title

125

Publisher

AIP Publishing

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All rights reserved
Sponsorship
European Research Council (279361)
Engineering and Physical Sciences Research Council (EP/M010589/1)
European Research Council (307636)
ER-C Lindemann Trust Fellowship
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