Defects induced by irradiation with fast electrons and 60Co γ-rays in O-rich Ge crystals were studied by means of infra-red absorption, deep-level transient spectroscopy and Hall-effect measurements. It was found that the vacancy-O (V-O) complex in Ge had 3 charge states (doubly negative, singly negative and neutral) and 2 corresponding energy levels in the gap at about Ec - 0.21eV and Ev + 0.27eV. Three absorption bands at 621.4, 669.1 and 716.2/cm were identified as O-related asymmetrical stretching vibrations for the neutral, singly negatively charged and doubly negatively charged states of the V-O complex, respectively.

Radiation-Induced Defects and their Transformations in Oxygen-Rich Germanium Crystals. V.P.Markevich, V.V.Litvinov, L.Dobaczewski, J.L.Lindström, L.I.Murin, A.R.Peaker: Physica Status Solidi C, 2003, 0[2], 702-6