Effect of electrode material on impedance spectra of metal-polyethylene structures with carbon nanotubes

Abstract

The effect of an electrode material on electrical properties of a composite material based on super high molecular polyethylene (SHMPE) filled with carbon nanotubes has been studied using impedance spectroscopy. Using the method of replacing the sample by an equivalent electric circuit, it has been found that, depending on the electrode material, a blocking barrier with high active resistance and a space charge region adjacent to it arise in the interface region. It has been shown that the barrier height is controlled by surface electronic states of SHMPE and weakly depends on the electron work function of metal electrodes (Bardeen barrier). The characteristic times of electrical relaxation characterizing bulk and interface regions of the composite under study have been determined.

Carrier transport properties of nanocrystalline Er3N@C80

“…In general, an equivalent electric circuit of a metal/semiconductor/metal system can be represented by a parallel combination of the interfacial resistance (R i ) and capacitance (C i ) in series with a parallel arrangement of the bulk resistance (R B ) and capacitance (C B ). [24][25][26] In this study, both R i and C i are small enough and can be ignored. The bulk resistances at frequencies of 6.25 KHz and 5.0 MHz were plotted in Fig.…”

Transport properties of carriers through nanocrystalline Lu3N@C80/Au interface

“…In general, an equivalent electric circuit of a metal/semiconductor/metal system can be represented by a parallel combination of the interfacial resistance (R i ) and capacitance (C i ) in series with a parallel arrangement of the bulk resistance (R B ) and capacitance (C B ), [20][21][22] as drawn in the inset of Fig. 1(a).…”

ize Effects in Electrical Properties of Carbon-Polypropylene Composites

“…The experimental data presented above testify to a considerable dependence of the dc conductivity of composites on the size of conducting filler particles. One of the interpretations of this effect consists in the existence of localized electron states in the polypropylene matrix and the existence of an interphase boundary layer adjacent to the carbon filler particles, with the properties of the interlayer being distinct from the bulk electric properties of polypropylene [30][31][32][33][34]. Therefore, it should be accepted that charge carriers can move in this destructured layer.…”

“…The observed rather weak reduction of ′ with the frequency growth can be a high-frequency interval of lower-frequency relaxation processes associated with the relaxation of molecular dipoles in the polymeric matrix owing to the presence of additives of other substances inserted in the course of matrix fabrication [47,48], the recharge of localized electron states in the regions of the dielectric polymeric matrix adjacent to the conducting filler particles [30,32], or the specimen polarization near the electrode [33].…”

“…Concepts describing the specific electric properties of those layers have not been developed enough. They were used only in a few works, while analyzing the relationship between the dielectric permittivity of a composite and the concentration of a conducting filler in it [30][31][32][33][34].…”