Light-induced properties of Ru-doped Bi12TiO20 crystals

Abstract

Absorption, light-induced absorption, photoconductivity and dark conductivity measurements are performed on Bi12TiO20 (BTO) crystals doped with different concentrations of ruthenium. It is found that a higher ruthenium addition shifts the optical absorption to the near-IR spectral region in comparison with non-doped BTO crystals and the absorption changes increase with increasing Ru content. The dark conductivity follows the Arrhenius law with an activation energy of 0.89 eV. From the measured light-induced absorption and nonlinear photoconductivity the participation of a shallow level in the charge transport mechanism in Ru-doped BTO crystals is suggested. Highly Ru-doped BTO samples possess infrared sensitivity and holographic gratings are successfully recorded at 790 and 825 nm, respectively.