Ultra-thin titanium nitride films for refractory spectral selectivity

TL;DR

This paper presents a stable, ultra-thin titanium nitride-based optical resonator capable of high-temperature operation for selective near-infrared thermal emission, advancing refractory emitter design.

Contribution

It introduces a novel refractory spectral emitter using nanometer-thin titanium nitride films with demonstrated stability at over 1070 K.

Findings

Stable operation at temperatures exceeding 1070 K.

Demonstrated selective near-infrared thermal emission.

Potential for precise spectral tailoring using established fabrication processes.

Abstract

We demonstrate a selectively emitting optical Fabry-P\'erot resonator based on a few-nm-thin continuous metallic titanium nitride film, separated by a dielectric spacer from an optically thick titanium nitride back-reflector, which exhibits excellent stability at 1070 K against chemical degradation, thin-film instabilities and melting point depression. The structure paves the way to the design and fabrication of refractory thermal emitters using the well-established processes known from the field of multilayer and rugate optical filters. We demonstrate that a few-nanometer thick films of titanium nitride can be stable under operation at temperatures exceeding 1070 K. This type of selective emitter provides a means towards near-infrared thermal emission that could potentially be tailored to the accuracy level known from rugate optical filters.