Plasmon-Enhanced Properties of Metallic Nanostructures and Their Application to Direct Solar Absorption Receivers

Plasmon resonance in nanoscale metallic structures has shown its ability to concentrate electromagnetic energy into subwavelength volumes [1–3]. Metal nanostructures exhibit a high extinction coefficient in VIS and NIR spectrum due to their large absorption and scattering cross sections corresponding to their surface plasmon resonance [4]. Hence, they can serve as an attractive candidate for solar energy harvesting material. Nanofluids have been proven to increase the efficiency of the photothermal energy conversion process in direct solar absorption collectors (DAC) [5, 6]. Early work has evaluated the extinction coefficient impacts on DAC [7]. The present work extends this with a quantitative comparison between core-shell nanoparticle suspensions and solid-metal nanosphere suspensions in a DAC. Ultimately, this study seeks a better understanding of how to best utilize the plasmon resonance effect to maximize the efficiency of nanofluid-based DACs or other volumetric heating systems.