Joule heating induced negative differential resistance in free standing metallic carbon nanotubes

TL;DR

This paper investigates how Joule heating causes negative differential resistance in free-standing metallic carbon nanotubes, emphasizing the role of heat dissipation mechanisms in their electrical behavior.

Contribution

It introduces a semi-classical model combining transport and heat equations to explain the origin of negative differential resistance in free-standing nanotubes.

Findings

Negative differential resistance arises from poor heat removal in free-standing nanotubes.

Heat dissipation mechanisms significantly influence the shape of the IV characteristics.

Transport nonlinearities are linked to thermal effects at high electric bias.

Abstract

The features of the $IV$ characteristics of metallic carbon nanotubes (m-NTs) in different experimental setups are studied using semi-classical Boltzmann transport equation together with the heat dissipation equation to account for significant thermal effects at high electric bias. Our model predicts that the shape of the m-NT characteristics is basically controlled by heat removal mechanisms. In particular we show that the onset of negative differential resistance in free standing nanotubes finds its origins in strong transport nonlinearities associated with poor heat removal unlike in substrate-supported nanotubes.