Abstract
Light scattering by dislocations in groupβIII nitrides has been studied. The effects of dislocation strain field and hollow cores on light scattering have been investigated. It is 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 have hollow cores. Analytical expressions for differential cross sections of light scattering by edge and screw dislocations have been obtained. Transport cross sections for inβplane and transversal light polarizations have been calculated. Calculated spectral dependencies of the scattering cross sections show significant resonant enhancement of the light scattering in the vicinity of the absorption edge. An angle diffusion coefficient of light beam directions has been obtained that can be used for experimental determination of density, Burgers vectors and core radii of threading dislocations in IIIβnitride crystals by optical means. In crystal films with high dislocation density the exponential decay of laterally propagating light rays resulting from scattering by dislocations can exceed the decay related to light absorption. (Β© 2005 WILEYβVCH Verlag GmbH & Co. KGaA, Weinheim)