Simple far-field radiative thermal rectifier using Fabry-Perot cavities based infrared selective emitters.

We present a thermal rectification device concept based on far-field radiative exchange between two selective emitters. Rectification is achieved due to a large contrast between the two selective emitters' thermo-optical properties. 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 ratio increasing with temperature up to 19% for a temperature difference of ΔT=370  K. Further optimization would allow larger rectification values. The presented results might be useful for energy conversion devices, engineering of smart radiative coolers/insulators, and development of thermal logical circuits.