Separation of the Schottky barrier and polarization effects on the photocurrent of Pt sandwiched Pb(Zr0.20Ti0.80)O3 films

Photoelectric behavior of Pt sandwiched Pb(Zr0.20Ti0.80)TiO3 (PZT) films deposited on Pt∕Ti∕SiO2∕Si substrates by a sol-gel method was investigated by testing the short-circuit photocurrent under different film thicknesses. By poling the films step by step with increased magnitude and alternated direction of the dc electric field, interesting photoelectric behavior was found when the PZT films were in virgin or poled up/down state. The photocurrent was also strongly dependent on the film thickness. A simple model was proposed to separate the effects of interface Schottky barriers and bulk ferroelectric polarization of the film on the photocurrent of the Pt/PZT/Pt structure.