Temperature control of thermal radiation from heterogeneous bodies

TL;DR

This paper explores how nanoscale composite structures with phase-change materials can be engineered to control thermal radiation, achieving high emissivity and directivity through temperature localization and complex geometries.

Contribution

It introduces a novel approach combining fluctuating-volume current formulation with complex composite geometries to tailor thermal radiation at mid-infrared wavelengths.

Findings

Composite bodies exhibit high emissivity and partial directivity.

Shape and material dispersion influence radiation properties.

Temperature localization within GST enables control over emission characteristics.

Abstract

We demonstrate that recent advances in nanoscale thermal transport and temperature manipulation can be brought to bear on the problem of tailoring thermal radiation from compact emitters. We show that wavelength-scale composite bodies involving complicated arrangements of phase-change chalcogenide (GST) glasses and metals or semiconductors can exhibit large emissivities and partial directivities at mid-infrared wavelengths, a consequence of temperature localization within the GST. We consider multiple object topologies, including spherical, cylindrical, and mushroom-like composites, and show that partial directivity follows from a complicated interplay between particle shape, material dispersion, and temperature localization. Our calculations exploit a recently developed fluctuating-volume current formulation of electromagnetic fluctuations that rigorously captures radiation phenomena in structures with both temperature and dielectric inhomogeneities.