Vanadium interactions in crystalline silicon

Abstract

The properties of interstitial vanadium $({\mathrm{V}}_{i})$ in Si and its interactions with the vacancy and the self-interstitial, as well as with hydrogen, are calculated using first-principles techniques. The stable configurations, gap levels, and binding energies agree well with the available experimental data. The nudged-elastic-band method is used to calculate the activation energies for diffusion of ${\mathrm{V}}_{i}$ in various charge states. They range from 1.46 (for ${{\mathrm{V}}_{i}}^{+}$) to 2.04 eV (for ${{\mathrm{V}}_{i}}^{\ensuremath{-}}$). The (trigonal) ${{\mathrm{V}}_{i},\mathrm{H}}$ pair has a binding energy of 1.15 eV, a donor level at ${E}_{c}\ensuremath{-}0.61\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$, and possibly an acceptor level ${E}_{c}\ensuremath{-}0.07\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$. Substitutional vanadium $({\mathrm{V}}_{s})$ can also trap H interstitials and form electrically active ${{\mathrm{V}}_{s},\mathrm{H}}$ and ${{\mathrm{V}}_{s},\mathrm{H},\mathrm{H}}$ complexes.