Vacancies and Self-Interstitials in Germanium Observed by Perturbed Angular Correlation Spectroscopy

Abstract

Trapping of two different point defects produced by electron irradiation at ${}^{111}\mathrm{In}$ 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 ${E}_{V}+0.20\mathrm{eV}$ and, tentatively, a donor state for the interstitial close to the conduction band ( ${E}_{C}\ensuremath{-}0.040\mathrm{eV}$) 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.