Photoconductor-ferroelectric structure of ultrathin Langmuir-Blodgett films

The Langmuir-Blodgett (LB) preparation of multilayers ultrathin ferroelectric films consisting from vinylidene fluoride copolymer, P(VDEF-TrFE) and antrakhinon, is described. Films were deposited on a glass substrate with a semitransparent tin oxide electrode. The upper nontransparent electrode was created by evaporation of aluminum. The illumination was performed by a xenon lamp through a broadband filter and semitransparent electrode. The switching hysteresis loops were obtained at 100 Hz by means of the Merz dynamic method using virtual-ground pulse measurement system. The control of the switching was also performed by the Chinoweth method, based on the observation of the photopyroelectric signal. It was observed that illumination leads to a substantial increase of the ferroelectric polarization. The influence of the illumination on the ferroelectric switching was assumed to be due to the redistribution of the applied electric field between ferroelectric copolymer and antrakhinon.