A new atomistic model was proposed for the threading screw dislocation core in wurtzite gallium nitride. By combining elasticity theory and atomistic simulations, a new core configuration, having a double 6-atom ring structure, was revealed to be more energetically favourable than the previously known one having a single 6-atom ring structure. The new core configuration was fully coordinated and had both Ga–Ga and N–N homonuclear bonds at its centre. As the double 6-atoms ring core was free from dangling bonds, it was found to introduce less dispersed energy levels in the band-gap than the single 6-atoms ring core.

A New Atomistic Model for the Threading Screw Dislocation Core in Wurtzite GaN. I.Belabbas, J.Chen, G.Nouet: Computational Materials Science, 2012, 51[1], 206–16