Inferring the energy sensitivity and band gap of electronic transport in a network of carbon nanotubes

Abstract

Since the industrialization of single-phase nanomaterial-based devices is still challenging, intensive research focus has been given to complex materials consisting of multiple nanoscale entities, including networks and matrices of nanowires, nanotubes, nanoribbons, or other large molecules; among these complex materials, networks of carbon nanotubes are a typical example. Detailed knowledge of the energy sensitivity and band gap of electronic transport in such a material system is difficult to detect, despite its importance in electronic, energetic and sensing applications. Here, we propose a new methodology to obtain these quantities using the measured Seebeck coefficient at a certain temperature but different Fermi levels. We discover that the network consisting of semiconducting (11,10)-carbon nanotubes actually exhibits metallic transport at room temperature. It is also interesting to verify that intrananotube ballistic transport is dominant over diffusive scattering by long-range disorder, as well as the quantum hopping resistance at the contact points. The transport asymmetry ratio between the holes and electrons (1.75) is similar to the value observed in pristine graphene samples (1.50).

A divide-and-conquer method to improve performance in quantum transport calculations: conductance in rotated graphene nanoribbons side-contact junctions

“…Quantum transport is a wide field of study [1][2][3][4] for which there exist plenty of recursive methods to study it within the tight-binding approximation [5][6][7][8][9][10][11][12][13][14]. These methods are useful to calculate the Green's function, the transfer matrix, or the scattering matrix (S-matrix) of the system, which then can be used to obtain the transmission function T(E) at energy E [5,6].…”