Photoconductive properties of photorefractive sillenites grown in an oxygen-free atmosphere

We report on non-steady-state photocurrent measurements of photorefractive sillenites grown in an oxygen-free atmosphere. A sufficient increase in the photoconductivity of crystals grown in an argon atmosphere in the red region of the spectrum (λ=633 nm) was observed. We attribute such changes to the high density of oxygen vacancies, and we present investigations of the influence of oxygen vacancies on the energy spectrum and on the parameters of photoinduced carriers in photorefractive sillenites.