report on the influence of oxygen concentration on structural and electrical properties of the amorphous yttria-stabilized zirconia (YSZ) thin films which are the potential high-k gate dielectric material of organic thin film transistors (OTFTs). The films were prepared by the E-beam evaporation process. To investigate the influence of the oxygen flow rate on the structural and electrical properties of the YSZ films, X-ray diffraction, X-ray photoelectron spectroscopy, current density-electric field, current-voltage were carried out in this work. Oxygen vacancies are expected to be the most predominant type of defect in metal-oxide dielectrics. The leakage current density decreased mainly because of the reduction of oxygen vacancies with increasing oxygen flow rate. (c) 2006 The Electrochemical Society.