Broadband light absorption using a multilayered gap surface plasmon resonator

A broadband visible light absorber composed of multiple metal-dielectric-metal (MMDM) layers is proposed and numerically investigated. Dielectric layers of different thicknesses in the MMDM structure lead to multiple plasmon resonances at different wavelengths; as a result, efficient broadband absorption can be achieved under optimized conditions. We found that an average simulated absorption of 93 % was obtained over the entire visible spectrum of 400-700 nm by controlling the geometric parameters. Furthermore, the origin of the broadband absorption was studied, and the effects of the diameter and pitch of the pattern on the absorption were investigated. Our proposed structure with a periodic array of circular patterns represents a novel candidate for future applications in photovoltaic cells and thermal emitters.