Extraordinary Photon Transport by Near-Field Coupling of a Nanostructured Metamaterial with a Graphene-Covered Plate

TL;DR

This paper demonstrates a theoretical method to significantly enhance near-field radiative heat transfer between dissimilar materials using nanostructured metamaterials and graphene, achieving fluxes much higher than blackbody limits.

Contribution

It introduces a novel approach for strong near-field energy transfer between dissimilar materials via graphene coupling, with detailed analysis of physical mechanisms and parameter effects.

Findings

Achieved two orders of magnitude enhancement in spectral heat flux at 20 nm gap.

Total heat flux can reach 500 times the blackbody limit between 400 K and 300 K.

Enhanced transfer is enabled by surface plasmon coupling and dispersion relations.

Abstract

Coupled surface plasmon/phonon polaritons and hyperbolic modes are known to enhance radiative transport across nanometer vacuum gaps but usually require identical materials. It becomes crucial to achieve strong near-field energy transfer between dissimilar materials for applications like near-field thermophotovoltaic and thermal rectification. In this work, we theoretically demonstrate extraordinary near-field radiative transport between a nanostructured metamaterial emitter and a graphene-covered planar receiver. Strong near-field coupling with two orders of magnitude enhancement in the spectral heat flux is achieved at the gap distance of 20 nm. By carefully selecting the graphene chemical potential and doping levels of silicon nanohole emitter and silicon plate receiver, the total near-field radiative heat flux can reach about 500 times higher than the far-field blackbody limit between 400 K and 300 K. The physical mechanisms are elucidated by the near-field surface plasmon coupling with fluctuational electrodynamics and dispersion relations. The effects of graphene chemical potential, emitter and receiver doping levels, and vacuum gap distance on the near-field coupling and radiative transfer are analyzed in detail.