Design and Optimization of a Metamaterial Absorber for Solar Energy Harvesting in the THz Frequency Range

This research highlights the design and comprehensive analysis of a high-performance three-layer metamaterial absorber tailored for solar energy harvesting in the terahertz (THz) frequency range. The proposed absorber incorporates gold <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\text{Au})$</tex>, vanadium dioxide <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\left(\text{VO}_{2}\right)$</tex>, and silicon dioxide <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\left(\text{SiO}_{2}\right)$</tex> to attain near-unity absorption throughout an extensive spectral range. The design is optimized to utilize the distinctive optical and plasmonic characteristics of these materials, facilitating effective solar radiation absorption in the THz range. The absorber has a wide absorption bandwidth of 3.00 THz, spanning frequencies from 2.414 THz to 5.417 THz, with peak absorption approaching 99 %. This range renders it an exceptionally effective alternative for improving solar energy conversion. The absorber exhibits polarization insensitivity, guaranteeing consistent performance at different incidence angles. Theoretical simulations were conducted to optimize the metamaterial's geometric configuration and material composition, highlighting the essential function of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SiO}_{2}$</tex> as a dielectric spacer and the adjustable characteristics of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{V O}_{\text{2}}$</tex>, which facilitate dynamic absorption regulation. These findings underscore the absorber's potential for advanced solar energy harvesting devices.