A theoretical analysis was made of the scattering potentials which were associated with dislocations in a 2-dimensional electron gas. It was shown that dislocations acted mainly upon the free carrier mobility, via the potential which was associated with their linear electric charge, rather than upon their strain-field potentials. Two different experimental cases, both of which involved GaAlAs-GaInAs-GaAs samples, were considered. In one case, the samples contained long misfit dislocations that resulted from partial relaxation during epitaxial growth. In the other case, the samples contained dislocation segments that were introduced by plastic deformation. It was shown that, in the case of long misfit dislocations, the free carrier mobility parallel to the dislocations was unaffected by dislocations but was probably controlled by some form of tunnelling effect in the direction perpendicular to the lines. In the case of dislocation segments, the free carrier mobility was controlled (in both directions) by a diffusion process which could be described with the aid of a phenomenological potential.

Z.Bougrioua, J.L.Farvacque, D.Ferré: Journal of Applied Physics, 1996, 79[3], 1536-45