Influence of statistical distributions on the electrical properties of disordered and aligned carbon nanotube networks

3D modeling of CNT networks for sensing applications

“…In this work we are still assuming a resistive behavior, with a constant value around 10 MΩ, while for metal-metal junctions and semiconducting-semiconducting junctions we use values respectively around 250 kΩ and 500 kΩ. The dependence respect to the temperature is assumed to be significant only for the semiconducting-metal junctions, and it follows (6) where R MS0 is the nominal value and T 0 is a temperature reference. We are currently working on the implementation of the Schottky diode model for the metal-semiconducting junctions, since there are a few limitations with our approximation.…”

“…Lots of efforts have been dedicated to trying to model these complex networks, and so far only 2D models have been presented [6] [7]. In such models the number of junctions between different CNTs is overestimated and the current flow can be far away from the real behavior.…”

Electron percolation in realistic models of carbon nanotube networks

“…We have previously shown that electrical properties of a simple 2D network depend strongly on the statistical distribution of length, diameter, and orientation but weakly depend on the distribution of nanotube-nanotube junction resistance. 11 Here, we are extending our previous description of charge percolation to 3D, and we are exploring the effects of various degrees of nanotubes interpenetration and nanotube waviness on the electrical properties on disordered networks. In Section II, we describe our simulation procedure in detail.…”

“…While most of these studies conclude that the higher is the aspect (L/D) ratio the lower is the percolation threshold for charge transport, the predicted critical CNT density for percolation also depends on several other physical and structural properties of the assembly. 11 Nevertheless, we are forced to say, that most charge transport simulations can reproduce the experimental critical CNT density, but essentially by fixing the nanotubenanotube junction resistance to a more or less realistic value. 11 A more rigorous approach to reproduce experimental conditions would have been to improve the CNT network model, more specifically by considering that nanotubes are not totally straight and rigid objects and that they are not interpenetrating each other.…”

“…11 Nevertheless, we are forced to say, that most charge transport simulations can reproduce the experimental critical CNT density, but essentially by fixing the nanotubenanotube junction resistance to a more or less realistic value. 11 A more rigorous approach to reproduce experimental conditions would have been to improve the CNT network model, more specifically by considering that nanotubes are not totally straight and rigid objects and that they are not interpenetrating each other. In brief, carbon nanotubes can be flexible nanostructures sometimes described by a waviness or curliness ratio but they are invariably solid objects separated in space.…”