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Tapping the potential of solar thermal energy requires spectrally selective solar absorber coatings, which lead to high photothermal efficiency. Micro‐cavities are known to dramatically enhance or suppress light absorption and emission in a directional manner and are used in nanophotonics, photodetectors, lasing, etc. Here, a dielectric‐metal‐dielectric multilayer stack with an optical micro‐cavity of a 12 nm tungsten layer formed between two dielectric layers of transition metal oxide CuCo2O4 (CCO) is designed. The CCO‐W‐CCO thin film multilayers deposited on stainless steel substrate by DC‐radio frequency magnetron sputtering achieve a 90% solar absorptance for the entire solar spectrum and a thermal emittance of 19% for the infrared spectrum. Optimization of thicknesses of individual layers is achieved by numerical simulations done in COMSOL Multiphysics, thereby reproducing the optical properties of each layer. The simulation results satisfactorily reproduce the experimental reflectance and demonstrate maximum power dissipation in the metallic layer in visible as well as NIR regions. Nevertheless, CCO material characterizations reveal that the enhanced absorption over the entire solar spectrum could be attributed to the underlying spinel crystal structure and the nanostructure film morphology. [ABSTRACT FROM AUTHOR]

To meet the need to the "customized eco‐friendly" design of flexible solar materials in vivid colors, here, the solar kitchen foils are devised which are selective, omnidirectional, and colored. The experimental and simulation results enable drawing the roadmap of the fabrication of glowing, colored flat foils for diverse energy, packaging, and decoration purposes. A new gold‐free golden foil, i.e., mimicking gold optically and visually, is designed as a prototype for the sustainable fabrication of advanced colored foils with glowing colors, e.g., golden with no need to neither hazardous anodization nor dying processes. The solar foil performs based on the newly developed concept of the polarizonic interference allowing production of omnidirectional structural colors by a disordered plasmonic nanocomposite. As the specific highlight, selective reflective coloration by plasmonic dipoles in a hybrid dielectric host, i.e., the building block of ultrathin solar absorbers with tailored, vivid colors, on an aluminum foil is demonstrated. In terms of the production technique, the applied sputtering technique is simple, versatile, cost‐effective, and compatible with the industrial packaging, decoration, and solar absorber manufacturing processes. Thus, it holds great promise for creation of advanced, flexible, colored solar absorbers in a simple, scalable, and sustainable fashion. [ABSTRACT FROM AUTHOR]