Investigation of the photoelectric component of the light-induced resistance-drop mechanism in SrTiO3 crystals

The results of the experimental observation of the photovoltage in a SrTiO 3 crystal sample, which exhibits the light-induced resistance-drop effect, have confirmed the previously proposed model of the effect in its photoelectric part. However, in addition to the expected manifestation of the barrier photovoltage, one more source of photocurrent has been found. This source is attributed to the manifestation of the linear photogalvanic effect in the subsurface region of the crystal. It has been assumed that the main role in the generation of photogalvanic current can be played by dipole centers of the oxygen vacancy-triply charged titanium ion type, which are oriented by an electric field of the surface barrier.