The promise of the broad range of direct band gaps of the {Al, Ga, In}N system was limited by the crystal quality of current material. As grown defect densities of InN, when compared with the more mature GaN, were extremely high and InN was strongly influenced by these defects. This was particularly important due to the unusual position of the charge neutrality level of InN, leading to both the well-known surface charge accumulation and difficulties in p-type doping. While impurities and native defects clearly impact on the bulk carrier density in InN, the effects of threading dislocations on the electrical properties were still in dispute. Issues such as whether the dislocation line was charged or contained dangling bonds remained open. A global search was made for possible dislocation core reconstructions for a range of screw dislocations in wurtzite III-N material, utilizing empirical Stillinger-Weber inter-atomic potentials. In addition, an investigation was made of a wide range of non-stoichiometric core structures.

Global Search for Stable Screw Dislocation Cores in III-N Semiconductors. S.Kraeusel, B.Hourahine: Physica Status Solidi A, 2012, 209[1], 71-4