Light scattering by dislocations in group-III nitrides was studied. The effects of dislocation strain field and hollow cores on light scattering were investigated. It was found that the coreless edge dislocation and the edge dislocations with hollow cores both participate in light scattering. Screw dislocations contribute to light scattering only if they had hollow cores. Analytical expressions for differential cross sections of light scattering by edge and screw dislocations were obtained. Transport cross sections for in-plane and transversal light polarizations were calculated. Calculated spectral dependencies of the scattering cross sections showed significant resonant enhancement of the light scattering in the vicinity of the absorption edge. An angle diffusion coefficient of light beam directions was obtained that could be used for experimental determination of density, Burgers vectors and core radii of threading dislocations in III-nitride crystals by optical means. In crystal films with high dislocation density the exponential decay of laterally propagating light rays resulting from scattering by dislocations could exceed the decay related to light absorption.

Light Scattering by Dislocations in Group-III Nitrides. Y.T.Rebane, R.I.Gorbunov, Y.G.Shreter: Physica Status Solidi A, 2006, 202[15], 2880-7