Evidence for Phonon-Assisted Intertube Electronic Transport in an Armchair Carbon Nanotube Film

TL;DR

This study demonstrates that phonons facilitate coherent electron transport between nanotubes in an armchair carbon nanotube film, revealing a dominant phonon-assisted conduction mechanism at high temperatures.

Contribution

It provides the first evidence of phonon-assisted intertube electron transport in a macroscopic armchair nanotube film, combining experimental and atomistic modeling insights.

Findings

Phonon-assisted conductance dominates high-temperature transport.

Coherent intertube dynamics are unambiguously observed.

Armchair nanotube films are promising for room-temperature coherent electronics.

Abstract

The electrical conductivity of a macroscopic assembly of nanomaterials is determined through a complex interplay of electronic transport within and between constituent nano-objects. Phonons play dual roles in this situation: their increased populations tend to reduce the conductivity via electron scattering while they can boost the conductivity by assisting electrons to propagate through the potential-energy landscape. Here, we identify a phonon-assisted coherent electron transport process between neighboring nanotubes in temperature-dependent conductivity measurements on a macroscopic film of armchair single-wall carbon nanotubes. Through atomistic modeling of electronic states and calculations of both electronic and phonon-assisted junction conductances, we conclude that phonon-assisted conductance is the dominant mechanism for the observed high-temperature transport. The unambiguous manifestation of coherent intertube dynamics proves a single-chirality armchair nanotube film to be a unique macroscopic solid-state ensemble of nano-objects promising for the development of room-temperature coherent electronic devices.