Mg doping affects dislocation core structures in GaN

Aberration-corrected scanning transmission electron microscopy was used to investigate the core structures of threading dislocations in undoped GaN films with both high and low dislocation densities, and in a comparable high dislocation density Mg-doped GaN film. All a-type dislocations in all sampl...

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Published inPhysical review letters Vol. 111; no. 2; p. 025502
Main Authors Rhode, S K, Horton, M K, Kappers, M J, Zhang, S, Humphreys, C J, Dusane, R O, Sahonta, S -L, Moram, M A
Format Journal Article
LanguageEnglish
Published United States 09.07.2013
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Summary:Aberration-corrected scanning transmission electron microscopy was used to investigate the core structures of threading dislocations in undoped GaN films with both high and low dislocation densities, and in a comparable high dislocation density Mg-doped GaN film. All a-type dislocations in all samples have a 5/7-atom core structure. In contrast, most (a+c)-type dislocations in undoped GaN dissociate due to local strain variations from nearby dislocations. In contrast, Mg doping prevents (a+c)-type dislocation dissociation. Our data indicate that Mg affects dislocation cores in GaN significantly.
ISSN:1079-7114
DOI:10.1103/physrevlett.111.025502