Determination of the Intershell Conductance in Multiwalled Carbon Nanotubes

TL;DR

This paper investigates electron transport between shells in multiwalled carbon nanotubes, revealing that for short distances, current primarily flows through outer shells via tunnel-type conductance consistent with orbital overlap estimates.

Contribution

It provides the first quantitative measurement of intershell conductance in MWNTs, demonstrating tunnel-type transport and characterizing its dependence on shell overlap.

Findings

Intershell conductance is approximately (10 kΩ)^{-1}/μm.

Current mainly flows through outer shells for short electrode separations.

Transport mechanism is tunnel-type, consistent with π-orbital overlap estimates.

Abstract

We report on the intershell electron transport in multiwalled carbon nanotubes (MWNT). To do this, local and nonlocal four-point measurements are used to study the current path through the different shells of a MWNT. For short electrode separations $\lesssim$ 1 $\mu$m the current mainly flows through the two outer shells, described by a resistive transmission line with an intershell conductance per length of ~(10 k\Omega)^{-1}/$\mu$m. The intershell transport is tunnel-type and the transmission is consistent with the estimate based on the overlap between $\pi$-orbitals of neighboring shells.