Precursor defect to the vacancy-dioxygen center in Si

In a recent paper [Phys. Rev. B 50, 11 531 (1994)] we have tentatively attributed two new infrared bands at 914 cm ^-1 and 1000 cm^-1, in neutron-irradiated Czochralski-grown silicon, to a [VO+Oᵢ] structure that was considered to develop as an intermediate stage in the process of conversion of a VO center to a VO₂ complex upon heat treatment. As a continuation of this work, we further investigate [VO+Oᵢ] structure and the formation of intermediate defects. In addition, we present semiempirical calculations of the localized vibrational mode frequencies of the [VO+Oᵢ] defect. The results are consistent with the experimental observations. {} 1996 The American Physical Society.