Broadband light absorption of an Al semishell-MIM nanostrucure in the UV to near-infrared regions

Abstract

A plasmonic broadband light absorber, whose absorption is insensitive to incident angles and polarizations, in the UV to near-infrared regions is demonstrated. In experimental observations, the maximum average absorption of 83% over a wavelength range from 300 to 1000 nm was confirmed. Our proposed plasmonic absorber is based on a three-layer stack of metal-insulator-metal, and the top metal layer is nanostructured by colloidal lithography. This structure is composed of Al, which is an excellent and cost-effective plasmonic material. This fabrication simplicity and economical material allows us to produce a large-scale device of solar absorbers.