Scalable, “Dip‐and‐Dry” Fabrication of a Wide‐Angle Plasmonic Selective Absorber for High‐Efficiency Solar–Thermal Energy Conversion

TLDR

A room‑temperature galvanic‑displacement “dip‑and‑dry” method fabricates plasmonic nanoparticle‑coated foils with tunable spectral reflectance. The resulting foils achieve 0.96–0.97 solar absorptance up to 80°, 0.10 thermal emittance, stability to 200 °C, and provide a simple, inexpensive, environmentally friendly alternative to existing selective absorber fabrication methods.

Abstract

Abstract A galvanic‐displacement‐reaction‐based, room‐temperature “dip‐and‐dry” technique is demonstrated for fabricating selectively solar‐absorbing plasmonic‐nanoparticle‐coated foils (PNFs). The technique, which allows for facile tuning of the PNFs' spectral reflectance to suit different radiative and thermal environments, yields PNFs which exhibit excellent, wide‐angle solar absorptance (0.96 at 15°, to 0.97 at 35°, to 0.79 at 80°), and low hemispherical thermal emittance (0.10) without the aid of antireflection coatings. The thermal emittance is on par with those of notable selective solar absorbers (SSAs) in the literature, while the wide‐angle solar absorptance surpasses those of previously reported SSAs with comparable optical selectivities. In addition, the PNFs show promising mechanical and thermal stabilities at temperatures of up to 200 °C. Along with the performance of the PNFs, the simplicity, inexpensiveness, and environmental friendliness of the “dip‐and‐dry” technique makes it an appealing alternative to current methods for fabricating selective solar absorbers.