Ultra-thin titanium nitride films for refractory spectral selectivity [Invited]

Abstract

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