Enhanced Short Wavelength Infrared Absorption in Tri-Layer Metamaterials through Polymer Coating

A highly efficient absorption in the short wavelength infrared (SWIR) spectral region is essential for the advancement of technologies in energy harvesting, infrared detection, and thermal emission. This study presents a polymer-coated multilayer perfect absorber metamaterial (MPA) with enhanced performance in the SWIR range. The MPA structure comprises four layers: a Polymethyl Methacrylate (PMMA) polymer top layer, an array of circular Titanium Nitride (TiN) disks as the second layer, thin film of Zinc Oxide (ZnO) as the dielectric middle layer, and a thin Titanium Nitride (TiN) film as the bottom metallic layer. Our findings demonstrate that this MPA achieves near-perfect absorption of 99% at a wavelength of 1.3 µm. The absorption characteristics are further investigated with respect to various structural parameters to ensure better performance of the absorber. The absorber holds great potential for applications in energy absorption, infrared sensing, thermal emission, and related fields.