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

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.