Spectrally stable thermal emitters enabled by material-based high-impedance surfaces

TL;DR

This paper introduces stable, narrowband thermal emitters using epsilon-near-zero substrates that maintain consistent emission spectra despite changes in physical parameters, suitable for scalable energy and sensing applications.

Contribution

It presents a novel approach using ENZ-based high-impedance surfaces for stable thermal emission, avoiding complex nanofabrication.

Findings

Demonstrated stable emission spectra experimentally and numerically.

Achieved insensitivity to film thickness, angle, and polarization.

Compatible with large-area, low-cost manufacturing.

Abstract

Radiative thermal engineering with subwavelength metallic bodies is a key element for heat and energy management applications, communication and sensing. Here, we numerically and experimentally demonstrate metallic thermal emitters with narrowband but extremely stable emission spectra, whose resonant frequency does not shift with changes on the nanofilm thickness, the angle of observation and/or polarization. Our devices are based on epsilon-near-zero (ENZ) substrates acting as material-based high-impedance substrates. They do not require from complex nanofabrication processes, thus being compatible with large-area and low-cost applications.