The influence of Rh doping on the light-induced properties of Bi4Ge3O12 single crystals

Abstract

The influence of different doping concentrations of rhodium on the light-induced and holographic properties of BGO crystal is investigated. It is found that Rh addition generates sufficient density of traps for photoinduced charge carriers such that holographic gratings are successfully recorded in the blue-green spectral range. The measured steady state diffraction efficiency at 514 nm is 0.14%, which corresponds to a refractive index modulation of Delta n similar to 1.5 x 10(-6) for higher Rh concentration. A photochromic effect and nonlinear dependence of photoconductivity on light intensity are observed indicating deep level and shallow level contributions to the charge transport mechanism of Rh-doped BGO.