Graphene-based enhancement of near-field radiative-heat-transfer rectification

TL;DR

This paper demonstrates that adding graphene sheets to a near-field thermal rectifier significantly enhances heat flux asymmetry, leveraging graphene's influence on spectral and distance-dependent heat transfer properties for improved nanoscale thermal management.

Contribution

It introduces a graphene-enhanced near-field thermal rectifier, revealing how graphene modifies heat flux behavior and improves rectification efficiency in nanoscale devices.

Findings

Graphene sheets significantly increase rectification coefficient.

The enhancement is linked to changes in heat flux distance dependence.

Spectral analysis shows altered power-law behavior due to graphene.

Abstract

We present a thermal device based on the near-field interaction between two substrates made of a polar and a metal-insulator-transition material. As a result of the temperature dependence of the optical properties, this device acts as a thermal rectifier, implying a strong asymmetry in the heat flux when reversing the two temperatures. By covering both substrates with a graphene sheet we show a significant enhancement of rectification coefficient. By investigating the flux spectral properties along with its distance dependence, we prove that this enhancement is associated to a change in the power-law dependence of heat flux with respect to the separation distance in the electrostatic regime due to the presence of graphene sheets. Our results highlight the promising role of graphene-based hybrid structures in the domain of nanoscale thermal management.