Ferroelectric ceramic devices

Abstract

A method and apparatus is disclosed by which high voltage and current can produced by a polycrystalline ferroelectric ceramic material in response to incident light. Numerous applications of the ferroelectric ceramic material taking advantage of such properties thereof are further disclosed. The polycrystalline ferroelectric ceramic material is initially poled by the application thereto of a pulse of voltage of predetermined magnitude and direction. After being poled in such fashion, the application of light impinging on the various surfaces of the ferroelectric ceramic material will induce a consistant high voltage between select surfaces of the ferroelectric ceramic material. Upon disposing electrodes in conductive contact with the material, a current can be generated to a load attached thereacross. Importantly, the magnitude of the voltage produced upon the application of incident light is directly proportional to the remanent polarization of the ferroelectric ceramic material, and is further directly proportional to the length of the material, the polarity of the high voltage being dependent upon the polarity of the remanent polarization and being capable of being reversed when the remanent polarization is reversed. The open circuit voltages produced by the ferroelectric ceramic material are orders of magnitude higher than those which typically have been produced in the prior-art through the utilization of standard photovoltaic materials.