Selective thermal emission with thin films of polar materials

摘要

Selective thermal emitters are materials which emit in narrow wavelength bands, unlike blackbody emitters which emit uniformly over all wavelengths. Materials with tailored emission/absorption characteristics can be useful for applications in energy conversion, energy conservation, chemical, and bio-chemical sensing. Designing materials with different emission/absorption spectra can be useful for varied applications such as energy conversion, chemical, and bio-chemical sensing. In this paper, we show that thin films of polar dielectric materials can act as selective emitters in two frequency bands on either side of the restrahlen band(s) of the polar material due to multiple reflections within the thin films.