title: Mg doping affects dislocation core structures in GaN.
abstract: 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.
authors.affiliation: Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ, United Kingdom. sr583@cam.ac.uk
authors.forename: S K
authors.initials: SK
authors.lastname: Rhode
authors.forename: M K
authors.initials: MK
authors.lastname: Horton
authors.forename: M J
authors.initials: MJ
authors.lastname: Kappers
authors.forename: S
authors.initials: S
authors.lastname: Zhang
authors.forename: C J
authors.initials: CJ
authors.lastname: Humphreys
authors.forename: R O
authors.initials: RO
authors.lastname: Dusane
authors.forename: S -L
authors.initials: S-
authors.lastname: Sahonta
authors.forename: M A
authors.initials: MA
authors.lastname: Moram