Ultrabroadband Plasmonic Meta-Absorber Based on Hybrid Split Ring Nanostructures

Plasmonic meta-absorbers achieve broadband near-perfect absorption, which can be adjusted by modifying the individual meta-atoms. This study presents an ultrabroadband meta-absorber that is both angle-insensitive and polarization-independent. The meta-absorber exhibits peak absorbance values of 95.6% at 553 nm in the visible spectrum and 97.7% at 1174 nm in the near-infrared spectrum, with an average absorption of ~94% across the 400–1800 nm wavelength range. The ultrabroadband meta-absorber achieves an incident angle insensitivity for any linearly polarized light. Thus, the proposed absorber is ideal for use as nanostructured coatings in thermophotovoltaic systems and as highly efficient thermal emitters.