The piezoelectric polarization and its associated charge density were calculated for edge, screw and mixed dislocations which were oriented parallel to the c-axis of the wurtzite nitride. It was shown that the polarization field which was generated by the screw components of dislocations was divergence-free, and therefore did not generate electric fields. The edge dislocations produced polarization fields that had non-zero divergence only at interfaces. Such characteristics minimized the electrical and optical effects of dislocations mediated by the piezoelectric effect.

Piezoelectric polarization associated with dislocations in wurtzite GaN C.Shi, P.M.Asbeck, E.T.Yu: Applied Physics Letters, 1999, 74[4], 573-5