Multifunctional Broadband Absorber Combining Solar Absorption, Thermal Emission, and Energy Conversion

Most metasurface absorbers focus on either absorption, emission, or solar‐to‐electrical conversion and often degrade at oblique incidence. We present a nickel‐polyimide‐nickel metasurface that unifies all three functionalities within a single structure. The design delivers over 90% absorption from 134.09–1674.70 THz (179.14–2237.3 nm) with an average of 96.40%, maintains above 80% from 97.54 to >3500 THz, and reaches 99.3% at multiple resonances. It achieves 97.30% solar absorption efficiency, near‐blackbody thermal emission rising to 95% at 3500 K, and 66.41% solar‐to‐electrical conversion at 1000 K. The design is polarization‐insensitive and stable up to 50° incidence for absorption ≥85%, ensuring reliable performance under practical conditions. By combining broadband absorption, efficient emission, and solar‐to‐electrical conversion in one architecture, the proposed design establishes a multifunctional platform with strong potential for advanced solar‐thermal and thermophotovoltaic applications.