Investigations of atomic configurations of 60 degrees basal dislocations in wurtzite GaN film by high-resolution transmission electron microscopy

GaN epitaxial films grown on Si (111) substrates were observed using a 200 kV high-resolution (HR) transmission electron microscope. Both perfect and dissociated 60 degrees basal dislocations were found in [2 (1) over bar(1) over bar0] HR images. By utilizing the image deconvolution method, the HR images were transformed into structure maps with an improved resolution, and then the atomic configurations of perfect and partial dislocations were determined. Afterwards, the possible dissociation schemes for the dissociated dislocations were derived.