Near-Perfect Absorption of Light by Plasmene Sheets

Abstract: Near-perfect absorbers (NPAs) efficiently absorb visible light with a layered nanostructure that is thinner than the diffusion lengths of photogenerated charge carriers. We overcame existing limitations in fabricating their nanoparticulate surface by depositing \textit{plasmene}, a tightly-packed two-dimensional lattice of metal nanoparticles formed through self-assembly. The plasmene NPAs absorb up to 98\% of incident visible light, with modelling showing the improvement on existing NPAs arises from the structural ordering of the plasmene. We also demonstrate control of NPAs' absorption profile through the use of anisotropic building blocks in plasmene. These property enhancements may broaden the application of NPAs to structural colour, sensing and photocatalysis.