Schottky barrier effects in the photocurrent of sol–gel derived lead zirconate titanate thin film capacitors

Abstract

We studied the photoresponse of Pb(Zr0.53Ti0.47)O3 (PZT) thin films by measuring the current–voltage (I–V) curve at several ferroelectric polarization states illuminated by a monochromatic 3.5 eV UV light. The photocurrent in Pt/PZT/Pt capacitors was sensitive to the polarization state, and the poling voltage-dependent photocurrent showed very asymmetric hysteresis behavior. The capacitance that is dependent upon the thickness of the samples was first measured. Then, the capacitance of the interfacial layer at a state with no interdiffusion between Pt and PZT film was extrapolated by using an equivalent circuit model. The result of the extrapolation was 28.1 μF/cm2.