A computationally efficient method for calculating the maximum conductance of disordered networks: Application to 1-dimensional conductors

TL;DR

This paper introduces a fast computational method to calculate the maximum conductance of disordered nanowire networks, aiding the design of transparent conductive films with improved electrical properties.

Contribution

A simple, efficient computational approach for conductance calculation in disordered nanostructured networks, adaptable to realistic tunneling-based film conductivity modeling.

Findings

Conductance depends on average connections per wire.

Network conductance varies with wire-electrode connections.

Inter-/intra-wire hopping ratios significantly affect conductance.

Abstract

Random networks of carbon nanotubes and metallic nanowires have shown to be very useful in the production of transparent, conducting films. The electronic transport on the film depends considerably on the network properties, and on the inter-wire coupling. Here we present a simple, computationally efficient method for the calculation of conductance on random nanostructured networks. The method is implemented on metallic nanowire networks, which are described within a single-orbital tight binding Hamiltonian, and the conductance is calculated with the Kubo formula. We show how the network conductance depends on the average number of connections per wire, and on the number of wires connected to the electrodes. We also show the effect of the inter-/intra-wire hopping ratio on the conductance through the network. Furthermore, we argue that this type of calculation is easily extendable to account for the upper conductivity of realistic films spanned by tunneling networks. When compared to experimental measurements, this quantity provides a clear indication of how much room is available for improving the film conductivity.