Effect of Interfaces on the Properties of Polycrystalline Thin-Film PZT Ferroelectric Capacitors

Abstract

A photocurrent directed opposite to ferroelectric (FE) polarization is observed in short-circuit thin-film polycrystalline Pt/PZT/Ir structures. The direction and magnitude of photocurrent are defined by the sign and magnitude of the FE polarization. A model based on a photovoltaic effect with characteristics determined by polarization of PZT grains is proposed. The model considers the field interaction of FE polarization charge with the charge carriers in intergranular PbO channel. Thin-film FE capacitor is considered as a photosensitive heterogeneous medium, where the conduction of PbO channels along PZT grain boundaries is controlled by FE polarization.

Origin of photoresponse in heterophase ferroelectric Pt∕Pb(ZrTi)O3∕Ir capacitors

“…Measuring short-circuit PC in these structures, 7 we found that although the PC is controlled by the magnitude of polarization and is always directed opposite to polarization, it is not the depolarization current of the ferroelectric. Measuring short-circuit PC in these structures, 7 we found that although the PC is controlled by the magnitude of polarization and is always directed opposite to polarization, it is not the depolarization current of the ferroelectric.…”