A simple radiative thermal diode

TL;DR

This paper introduces a simple radiative thermal diode using selective emitters with temperature-dependent properties, achieving unprecedented rectification ratios for thermal radiation control.

Contribution

It proposes a novel thermal rectification device based on far-field radiative exchange with multilayer emitters, achieving high rectification ratios not previously attained.

Findings

Achieved up to 70% rectification with 200 K temperature difference

Device uses multilayer metallic and semiconductor films

Potential for further optimization and applications in energy and thermal management

Abstract

We present a thermal rectification device concept based on far-field radiative exchange between two selective emitters. Rectification is achieved due to the fact that one of the selective emitters radiative properties are independent on temperature whereas the other emitter properties are strongly temperature dependent. A simple device constituted by two multilayer samples made of metallic (Au) and semiconductor (Si and HDSi) thin films is proposed. This device shows a rectification up to 70% with a temperature difference \Delta T = 200 K, a rectification ratio that has never been achieved so far with radiation-based rectifiers. Further optimization would allow larger rectification values. Presented results might be useful for energy conversion devices, smart radiative coolers / insulators engineering and thermal modulators development.