Photovoltaic effects and its oxygen content dependence in BaTiO3-δ/Si heterojunctions

Three oxide heterojunctions made of BaTiO3-delta/Si have been fabricated under various oxygen pressures by laser molecular beam epitaxy. They all exhibited nonlinear and rectifying I-V characteristics but with a large difference in the rectification behaviors. Their photoelectric properties and dependences on oxygen contents in BaTiO3-delta films have been experimentally studied. We found that the photovoltaic effects depended strongly on the oxygen contents of the BaTiO3-delta films. The possible mechanism was proposed based on the band structure of the p-n heterojunctions. (C) 2008 American Institute of Physics.