INFLUENCE OF THE ALTERNATING FIELD FREQUENCY ON THE ELECTROPHYSICAL PROPERTIES OF POLYMER FILMS

Abstract

The results of an experimental study of the frequency dependences of the impedance of metal-polymer-metal sandwich structures for different thicknesses of the polymer layer are presented. The voltage characteristics of the samples in various frequency ranges were measured. The general view of the amplitude-frequency characteristics graphs for all film thicknesses is well described by the theoretical model of the sequential RC circuit. On all graphs, you can notice the presence of a cutoff frequency, which can be interpreted as the beginning of the RC filter. However, there are also significant deviations from the theoretical characteristics. It is established that with a polymer layer thickness of 80 nm in the frequency range At 10-40 Hz, an abnormal decrease in impedance is observed, corresponding to an increase in current at the volt-ampere characteristics. The resulting charge instability is considered as a consequence of the volume-charge polarization, which, in turn, is due to the specifics of polymer-polymer interfaces that arise during the formation of the supramolecular structure of the polymer. The results of the work are interpreted within the framework of the resistive switching model, which assumes that in the case of submicron polymer films used in the metalpolymer-metal system, resistive switching is possible as a result of the sequential transformation of the energy electronic subsystem of the polymer film under the action of charge injection from the electrodes.