Affecting point defects in SrTiO3 by preparation and illumination

Fe doped SrTiO3 thin films produced by pulsed laser deposition from a stoichiometric target exhibit an astonishingly low conductivity compared to bulk samples. This extraordinary difference of five orders of magnitude is attributed to a Sr nonstoichiometriy causing Sr vacancies and anti-site defects. In the second part of this talk, the effects of UV irradiation on SrTiO3 are discussed. Oxygen incorporation is accelerated causing a change in the material’s composition, which leads to high temperature photochromism, a battery-type of voltage, and an enhanced conductivity. A mechanistic explanation based on quasi fermi levels is suggested.