Influence of sample thickness on the measurement results of permittivity of polymer-based dielectrics: Role of electrode polarization

Abstract

Polymer-based dielectrics are widely used in thin film capacitors. Accurate measurement of the dielectric properties of those materials is the premise and basis for evaluating or analyzing the energy storage characteristics of thin film capacitors. In this paper, the influence of thickness on the permittivity of polymer-based materials is studied. The results show that for the dielectrics with high conductivity, the permittivity measurement results show an increasing trend with the increase in the thickness of the sample. For dielectrics with low conductivity, there is no significant correlation between thickness and measured permittivity. Through the analysis of this phenomenon, it is indicated that the effect of the thickness on permittivity measurement results is caused by electrode polarization, and the relationship between permittivity measurement results and thickness under the influence of electrode polarization is given. The experimental results are in good agreement with the theoretical analysis. Based on the model proposed in this paper, the influence of thickness on the measurement results when measuring the permittivity of polymer-based dielectrics can be effectively eliminated, so as to obtain the true permittivity of the dielectrics. The results of this study provide strong support for accurately studying the dielectric properties of polymer film materials and the effect of electrode polarization on the dielectric behavior of metal–insulator–metal structures.