Superior Performance of Hollow Plasmonic Cubic Structures for Solar Energy Harvesting, Conversion, and Storage Systems

The remarkable optical properties of metallic nanoparticles play a pivotal role in enhancing light absorption for solar energy applications by efficiently converting solar flux into heat. In the pursuit of achieving a broad spectrum absorption from visible to near-infrared (NIR) wavelengths, colloidal nanoparticles, specifically gold/silver hollow nanocubes (HNC) with varied aspect ratios, are utilized. Employing a comprehensive full-wave field analysis, we assess the linear optical characteristics to determine the solar-weighted absorption coefficient of these plasmonic nanofluids across different concentrations and aspect ratios. Our findings reveal that the solar-weighted absorption efficiency of gold hollow plasmonic nanocubes significantly improves (up to 93 %) even at extremely low volume fractions (p = 3.10 \(^{-6}\) ${}^{-6}$ ) compared to silver hollow plasmonic nanocubes (83 %). The outstanding performance of Au hollow plasmonic nanocubes, boasting over 99 % enhancement in solar-weighted absorption efficiency at minimal nanofluid thickness (1.0 cm), underscores their Ag counterparts, marking a significant leap forward in ideal solar absorber conditions.