Electrical Properties of Plastically Deformed Germanium

Samples of Sb-doped (10 ohm-cm $n$-type) and Au-doped (20 ohm-cm $p$-type) Ge have been plastically deformed at 550°C-620°C. The deformation created a large concentration of acceptor centers distributed inhomogeneously throughout the deformed sections of the samples. These acceptors lie near the valence band and converted the Sb-doped specimens to $p$-type. Hall coefficient measurements have been made as a function of temperature to determine the energies of these acceptors. Upon annealing at temperatures above 750°C from 30 minutes to 1½ hours, the acceptor levels near the valence band disappear, leaving only the acceptors probably associated with edge dislocations. It is postulated that the annealable acceptors may be due to the presence of vacancies.