The atomic and electronic structures of threading edge dislocations were investigated by using self-consistent charge density functional tight-binding approaches. Full-core, open-core, Ga-vacancy and N-vacancy edge dislocations were fully relaxed in the present total-energy scheme. It was found that the Ga-vacancy dislocation was the most stable in a wide range of Ga chemical potentials, whereas full-core and open-core dislocations were the most stable in the Ga-rich region. In all cases, partial dehybridization took place during lattice relaxation near to the dislocation. The dangling bonds at Ga atoms mainly contributed to the deep-gap states, whereas those at N atoms contributed to the valence-band tails. All of the edge dislocations could act as deep trap centres; except for the Ga-vacancy dislocation, which could be the source of yellow luminescence.

Electronic Structures of GaN Edge Dislocations. S.M.Lee, M.A.Belkhir, X.Y.Zhu, Y.H.Lee, Y.G.Hwang, T.Frauenheim: Physical Review B, 2000, 61[23], 16033-9