Electrical conductivity of thin films grown by deposition of random clusters of particles

摘要

Extensive numerical simulation of the frequency-dependent effective conductivity of porous thin films, grown by deposition of clusters of elementary particles with various shapes and sizes, as well as rodlike particles has been analyzed and reported. The dependence of frequency-dependent effective conductivity σ_e(s) of films on their morphology has been studied. The conductivity variations versus the size of deposited clusters have been investigated which show a decreasing function behavior. Also, the conductivity depends on the frequency s by a power law whose exponent is non-universal, but depends weakly on the size of the clusters. The non-universality of the exponent is in agreement with the experimental data for the electrical conductivity of a wide variety of materials. In order to study the important characteristic of well-connected materials, the direct current conductivity as a function of films' stationary porosity has been investigated which shows an essentially linear function. It also grows as a power law with the thickness of the film, which is also in agreement with the past experimental data.