Shallow dislocation states in Ge. Thermal treatment effects

Abstract

The effects of thermal treatments on the carrier density of Ge deformed at relatively low temperature are examined. The results are explained by considering a progressive inactivation of shallow states at ≈ 0.02 eV from the valence band, probably connected with the strain field around the dislocations, and by referring the behaviour after prolonged heating to dislocation states at 0.05 to 0.06 eV, probably due to impurity diffusion along the dislocations themselves. Indication is found that other acceptor centres are introduced in bulk Ge together with the dislocations, during deformation and thermal treatments.