Structure and electronic properties of mixed (a plus c) dislocation cores in GaN

Classical atomistic models and atomic-resolution scanning transmission electron microscopy studies of GaN films reveal that mixed (a + c)-type dislocations have multiple different core structures, including a dissociated structure consisting of a planar fault on one of the {1 (2) over bar 10} planes terminated by two different partial dislocations. Density functional theory calculations show that all cores introduce localized states into the band gap, which affects device performance. (C) 2014 AIP Publishing LLC.