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

We studied the photoresponse of Pb(Zr0.53Ti0.47)O-3 (PZT) thin films by mea suring the current-voltage (I-V) curve at several ferroelectric polarizatio n states illuminated by a monochromatic 3.5 eV UV light. The photocurrent i n Pt/PZT/Pt capacitors was sensitive to the polarization state, and the pol ing voltage-dependent photocurrent showed very asymmetric hysteresis behavi or. 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 mu F/cm (2). (C) 2000 American Institute of Physics. [S0003-6951(00)03306-4].