Vacancies and self-interstitials in germanium observed by perturbed angular correlation spectroscopy

Trapping of two different point defects produced by electron irradiation at In-111 probes is studied as a function of the Fermi level in germanium by perturbed angular correlation spectroscopy. The defects are identified as monovacancies and self-interstitials, respectively. An acceptor state for the vacancy at E-v + 0.20 eV and, tentatively, a donor state for the interstitial close to the conduction band (E-c - 0.040 eV) is deduced from the trapping behavior. Long range migration of the neutral vacancy and the positive interstitial takes place at 200 and 220 K, respectively.