Strain of single edge dislocations in bulk GaN

Abstract

An edge dislocation causes a strain dipole field with compressive strain on one and tensile strain on the other side of the dislocation. We observe this strain dipole of single edge dislocations through the tiny spectral shift it causes to the narrow lines of the donor bound exciton at low temperatures. We demonstrate that the microscopic orientation of the Burgers vector given by the hexagonal lattice causes the orientation of these strain dipoles along six discrete directions at macroscopic scale. We also introduce a two-dimensional convolution method using a complex convolution core for an accurate determination of the strain dipole orientation. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)