Preparation and photovoltaic properties of lead lanthanum zirconate titanate in design of multilayers

In this paper, we report on the formation of multilayer structures and the highly improved photovoltaic output current of the lead lanthanum zirconate titanate (PLZT) film employed. The photovoltaic effect of ferroelectrics has the advantage of simple mechanisms of nonbias applications, which are indispensable for semiconductor p-n junctions. However, the output current of PLZT bulk is too low for use as a device current source. The new design is described using an upper transparent indium tin oxide (ITO) electrode. The PLZT film structure exhibits a μA output current upon light illumination. The photovoltaic current of the PLZT film is more than 10² times that of the bulk PLZT. These differences are due to the characteristics of the design of multilayers including the configuration of the electrode. The PLZT film also has the advantages of easy output control and suitability for use on a Si substrate. A simple model is used for an illustrative explanation of the improved photovoltaic effect of the PLZT film. Results show that the photovoltaic effect of the ferroelectric multilayer is useful as the current source for a micro-electro-mechanical system (MEMS).