Photoreceptor characteristics of barium titanate/polyvinylidene fluoride composite film

Abstract

The photoferroelectric barium titanate (BaTiO3)/polyvinylidene fluoride (PVDF) composite films in the ratio 70:30 are found to possess good photosensitivity in the visible region of the spectrum. Results on the investigations of charge generation, trapping, recombination, discharge, and retention properties of the composite film are presented in this paper. The dark polarization and dark depolarization characteristics of the film show that it can accept and retain very high charge for a very long time. The charge decay properties of the dark polarized and photo depolarized electrosensitized sample indicate that it can be used successfully in electro-photographic applications as the dark decay is found to be slow while the light decay is very fast. In addition to this, the photo polarization and photo depolarization studies of the polarized films show that the film has very good remnant polarization,which persists for several hours to days. The persistence of polarization, its magnitude, and the decay characteristics depend on the charging conditions. The resultant dark and photo depolarization current values are found to increase linearly with increase of the poling field, illumination intensity, and poling time. The polarization properties of the film are comparable to that of the BaTiO3 single crystal. The results of the studies show that BaTiO3IPVDF composite films may find many interesting applications as a photoreceptor in the fields of electrophotography, holography, and optical memory. It may also be useful as a photorefractive nonlinear optical material.