Oxygen-Defect Complexes in Neutron-Irradiated Germanium

Abstract

The recovery processes in neutron‐irradiated oxygen‐doped germanium have been studied by measuring the growth and decay of infrared absorption bands associated with oxygen‐defect complexes. After a neutron irradiation at −50°C, the absorption band assigned to the stable oxygen‐vacancy complex is barely detectable but increases upon annealing to 50°C. These results indicate that additional vacancies are produced by the dissociation of the large defect clusters formed by neutron irradiation. Annealing to higher temperatures produces the same bands in the same sequence as those which developed in the spectra of electron irradiated samples upon annealing. Comparisons of the annealing curves of the absorption bands produced by the two types of irradiations, however, reveal a general shift to higher annealing temperatures for the neutron‐irradiated samples. These temperature shifts are interpreted as resulting from changes in equilibria of the oxygen‐defect complexes caused by the dissociation of clusters into simpler defects. No similar evidence for the presence of clusters above annealing temperatures of 350°C was observed.