Ultra-wideband multifunctional high-performance solar energy harvester as thermal emitter

Conventional broadband absorbers for solar energy harvesting usually suffer from limited frequency coverage, polarization sensitivity, reduced thermal stability and complex fabrication requirements, which restrict their practical deployment in photothermal and thermo photovoltaic systems. To address these limitations, a broadband polarization-insensitive metasurface absorber is proposed in a metal-dielectric-metal configuration. The hybrid pattern combining nickel and polyimide enables multiple overlapping resonances through strong electromagnetic coupling and efficient impedance matching, achieving an ultra-broadband absorption from 125.74 to 5827.1[Formula: see text]THz (51.44–2384.6[Formula: see text]nm) with an average absorption of 93.8% and maintaining over 80% absorption beyond 6000[Formula: see text]THz. The proposed design attains a normalized solar absorption efficiency of 93.84% over the AM-1.5 spectrum and a thermal emission efficiency of 93.41% at 3500[Formula: see text]K, closely approximating ideal blackbody behavior. Solar-to-electrical conversion efficiency reaches up to 64.80% under high solar concentration. The design exhibits complete polarization insensitivity and maintains angular stability up to 60[Formula: see text] and 70[Formula: see text] for absorption levels of [Formula: see text]90% and [Formula: see text]80%, respectively. Combining superior optical performance, thermal stability and simple fabrication, the proposed absorber overcomes key limitations of previous designs and shows strong potential for next-generation solar energy harvesting, hybrid photovoltaic-thermal systems and infrared thermal emitters.