Interface layer thickness effect on the photocurrent of Pt sandwiched polycrystalline ferroelectric Pb(Zr,Ti)O3 films

Based on the analysis of the photocurrent behavior of Pt sandwiched Pb(Zr0.2Ti0.8)O3 (PZT) films, the experimental evidence of top Pt/PZT interface layer thickness effect on the photocurrent is reported. It was well established before that the photocurrent of metal/ferroelectric film is attributed to the height of Schottky contact barrier. However, our results suggest that the photocurrent of Pt/PZT interface contact is determined not only by the barrier height but also by the interface layer thickness, namely, by the built-in electrical field at the interface layer. The mechanism behind such photocurrent phenomenon is proposed.