It was recalled that experimental investigations of plastically deformed elemental and III-V semiconductors had proved that high numbers of vacancies and vacancy clusters were formed. The formation of point defects by the motion of jogged dislocations was analysed. Vacancies which formed behind jogs were unstable as a simple chain of vacancies. They instead transformed immediately into stable 3-dimensional agglomerates. The stability of various vacancy clusters was investigated by means of density-functional calculations. The positron lifetime in such clusters was calculated and was compared with experimental results. An association of open-volume defects with the dislocations could be derived from positron lifetime measurements. The analysis of a positron-trapping mode characterized the dislocation as being a combined defect. The undisturbed dislocation line was a precursor trap for positron capture in a deep trap which was related to vacancies that were bound to the dislocation.

Vacancy Clusters in Plastically Deformed Semiconductors. H.S.Leipner, C.G.Hübner, T.E.M.Staab, M.Haugk, A.Sieck, R.Krause-Rehberg, T.Frauenheim: Journal of Physics - Condensed Matter, 2000, 12[49], 10071-8