Spatially-Resolved Temperature Measurements of Electrically-Heated Carbon Nanotubes

TL;DR

This study uses spatially-resolved Raman spectroscopy to analyze temperature profiles and thermal transport mechanisms in electrically-heated individual carbon nanotubes, revealing size-dependent heating effects and thermal properties.

Contribution

It provides the first detailed spatial temperature profiles of suspended carbon nanotubes under electrical heating, elucidating phonon decay, thermal contact resistance, and thermal conductivity variations.

Findings

Unequal temperature profiles in G+ and G- bands.

Short nanotubes exhibit more pronounced preferential heating.

Direct estimates of thermal contact resistance and thermal conductivity variation.

Abstract

Spatially-resolved Raman spectra of individual pristine suspended carbon nanotubes are observed under electrical heating. The Raman G+ and G- bands show unequal temperature profiles. The preferential heating is more pronounced in short nanotubes (2 um) than in long nanotubes (5 um). These results are understood in terms of the decay and thermalization of non-equilibrium phonons, revealing the mechanism of thermal transport in these devices. The measurements also enable a direct estimate of thermal contact resistances and the spatial variation of thermal conductivity.