Electronic structure of threading dislocations in wurtzite GaN

We have carried out atomistic simulations, based on density functional theory, to investigate the atomic and electronic structures of the three types of prismatic threading dislocations in hexagonal gallium nitride. Screw and mixed threading dislocations were demonstrated to introduce both deep and shallow gap states, while most of core configurations of the edge dislocation introduce solely shallow states. The higher electrical activity of both screw and mixed dislocations, compared to the edge one, is correlated with the high dispersion of their energy levels, within the GaN bandgap. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)