Thermal Probing of Energy Dissipation in Current-Carrying Carbon Nanotubes

TL;DR

This study uses scanning thermal microscopy to measure temperature profiles in current-carrying carbon nanotubes, revealing heat dissipation mechanisms and transport behaviors in multi-walled and single-walled nanotubes.

Contribution

It provides detailed experimental insights into heat dissipation pathways and electron transport regimes in carbon nanotubes under electrical bias.

Findings

Most Joule heat in multi-walled nanotubes is conducted to metal contacts.

Majority of heat in single-walled nanotubes is transferred across the nanotube-substrate interface.

Temperature rise ranges from 5 to 42 K per micro watt of Joule heating.

Abstract

The temperature distributions in current-carrying carbon nanotubes have been measured with a scanning thermal microscope. The obtained temperature profiles reveal diffusive and dissipative electron transport in multi-walled nanotubes and in single-walled nanotubes when the voltage bias was higher than the 0.1-0.2 eV optical phonon energy. Over ninety percent of the Joule heat in a multi-walled nanotube was found to be conducted along the nanotube to the two metal contacts. In comparison, about eighty percent of the Joule heat was transferred directly across the nanotube-substrate interface for single-walled nanotubes. The average temperature rise in the nanotubes is determined to be in the range of 5 to 42 K per micro watt Joule heat dissipation in the nanotubes.