Broadband Thin Film Absorber Based on Plasmonic Nanoparticles

Harvesting solar energy presents a formidable challenge, primarily rooted in the need to capture light across a broad spectrum range efficiently. Addressing this challenge, we describe the concept of designing a broadband perfect absorber in the form of a thin-film system with plasmonic nanoparticles as its foundational basis. We study a thin-film absorber made from the scattering responses of an Au144 gold molecule. It turns out that this thin-film absorber absorbs the light in the entire visible light region quite well. As a further aspect, we employ bulk copper nanoparticles as the basis for the nanoparticle layer within the absorber. We inspect on computational grounds the effect of the nanoparticles filling factor and the thin-film thicknesses on the absorber performance. Remarkably, our findings reveal that the thin-film absorber with copper nanoparticles can absorb 90% of light energy across a broad spectrum ranging from ultraviolet to near-infrared wavelengths. To validate the accuracy of our simulations, we translate these optimized absorber layouts into fabrications together with experimental partners from the University of Kiel. ... mehrThe experimental results align remarkably closely with our simulations, confirming the capability of our designed broadband perfect absorber.