Experimental observation of nanoscale radiative heat flow due to surface plasmons in graphene and doped silicon

TL;DR

This study experimentally demonstrates that surface plasmons in graphene significantly enhance nanoscale radiative heat transfer, especially at short distances, with potential applications in photonics and energy devices.

Contribution

It provides the first experimental evidence of nanoscale radiative heat flow enhancement due to graphene plasmons, validating theoretical predictions.

Findings

Graphene's plasmons dominate heat transfer at short distances.

Enhanced heat flux observed with graphene on SiC.

Doped silicon measurements support plasmon influence.

Abstract

Owing to its two dimensional electronic structure, graphene exhibits many unique properties. One of them is a wave vector and temperature dependent plasmon in the infrared range. Theory predicts that due to these plasmons, graphene can be used as a universal material to enhance nanoscale radiative heat exchange for any dielectric substrate. Here we report on radiative heat transfer experiments between SiC and a SiO2 sphere which have non matching phonon polariton frequencies, and thus only weakly exchange heat in near field. We observed that the heat flux contribution of graphene epitaxially grown on SiC dominates at short distances. The influence of plasmons on radiative heat transfer is further supported with measurements for doped silicon. These results highlight graphenes strong potential in photonic nearfield and energy conversion devices.