Abstract
The electron-beam-induced-current (EBIC) mode of a scanning electron microscope has been used to characterize the electrical activity of the grain boundaries in germanium. The boundaries have also been characterized from a structural point of view using electron channelling patterns (ECP) and X-ray topography. The low-angle boundaries in Ge polycrystals show an EBIC contrast C which increases when the beam energy increases, while the Σ3 twins do not show a significant activity even when there is a deviation from the coincidence orientation. The collection efficiency η of Schottky contacts has been measured. Both C and η measurements cannot be quantitatively analysed using previously existing models. The basic ideas which should lead to a better modelling are discussed.