Nanophotonic engineering of far-field thermal emitters

TL;DR

This paper reviews how nanophotonic structures can be engineered to control far-field thermal emission, enabling advancements in energy harvesting, lighting, and cooling technologies.

Contribution

It provides a comprehensive overview of nanophotonic strategies to manipulate thermal emission spectra, directionality, and polarization, highlighting recent progress and applications.

Findings

Nanostructured materials can tailor thermal emission properties.

Engineered thermal emitters improve energy harvesting efficiency.

Applications include radiative cooling and advanced lighting.

Abstract

Thermal emission is a ubiquitous and fundamental process by which all objects at non-zero temperatures radiate electromagnetic energy. This process is often presented to be incoherent in both space and time, resulting in broadband, omnidirectional light emission toward the far field, with a spectral density related to the emitter temperature by Planck's law. Over the past two decades, there has been considerable progress in engineering the spectrum, directionality, polarization, and temporal response of thermally emitted light using nanostructured materials. This review summarizes the basic physics of thermal emission, lays out various nanophotonic approaches to engineer thermal-emission in the far field, and highlights several relevant applications, including energy harvesting, lighting, and radiative cooling.