Bistability of the Photoelectric Effect in Fullerene–Phthalocyanine Ferroelectric Composite Films

The photoelectric properties of thin films based on an organic composition of fullerene (C60), zinc phthalocyanine (ZnPc), and a ferroelectric copolymer of vinylidene fluoride with trifluoroethylene P(VDF–TrFE) are studied. Along with well-pronounced photoelectric properties (which are characteristic of fullerene–phthalocyanine mixtures), this material is shown to have ferroelectric properties as well. Ferroelectric switching of polarization is found to cause bistable switching of the photoelectric effect with a significant increase in the ampere–watt sensitivity in one of the polarized states. This effect is explained by a change in the built-in local electric field, which depends on the direction of the ferroelectric polarization vector and acts inside the cavities of the ZnPc/C60 molecular heterojunctions.