Tunable light harvesting with tailored disorder in plasmonic systems: induced vs materials effects

Abstract

Disorder allows us to overcome the trade-off between local enhancement of the electromagnetic field and bandwidth for plasmonic light harvesting. Here we will demonstrate a system where the spectral extent of light harvesting can be tuned via coupling a disordered plasmonic layer to an underlying Fabry-Perot cavity, allowing the transition from broadband absorption to narrow-band reflection. We examine the influence of the plasmonic material properties on the light harvesting response of our system, and demonstrate a regime where light harvesting from the far field is dominated via the interplay between the modes of the disordered system and the Fabry Perot cavity, with the actual material composition of the plasmonic layer only of secondary effect. This allows a de-coupling between the near- and the far-field response of our system: near-field enhancement in the disordered layer is dominated by the material, light-harvesting by the cavity geometry. Such a system shows promise for applications in light harvesting for energy conversion.