Evaluation of thermal stability in spectrally selective few-layer metallo-dielectric structures for solar thermophotovoltaics

•An extremely high-thermal-stability few-layer structure is proposed.•A HfO2 layer on a Mo substrate is more stable than that on a W substrate at 1473 K.•The degradation of the structure at 1473 K is due to Mo thin-film oxidation.•The potential stability of few-layer structures for high-temperature applications. The thermal stability of spectrally selective few-layer metallo-dielectric structures is evaluated to analyze their potential as absorber and emitter materials in solar thermophotovoltaic (STPV) systems. High-efficiency (e.g., STPV) systems require materials with spectrally selective properties, especially at high temperatures (>1273 K). Aiming to develop such materials for high-temperature applications, we propose a few-layer structure composed of a refractory metal (i.e., Mo) nanometric film sandwiched between the layers of a dielectric material (i.e., hafnium oxide, HfO2) deposited on a Mo bulk substrate. In vacuum conditions (