Broadband Absorption Engineering to Enhance Light Absorption in Monolayer MoS2
Here we take a first step toward tackling the challenge of incomplete optical absorption in monolayers of transition metal dichalcogenides for conversion of photon energy, including solar, into other forms of energy. We present a monolayer MoS2 based photoelectrode architecture that exploits nanophotonic light management strategies to enhance absorption within the monolayer of MoS2, while simultaneously integrating an efficient charge carrier separation mechanism facilitated by a MoS2/NiOx heterojunction. Specifically, we demonstrate two extremely thin photoelectrode architectures for solar fuel generation: (i) a planar optical cavity architecture, MoS2/NiOx/Al, that improves optical impedance matching and (ii) an architecture employing plasmonic silver nanoparticles (Ag NPs) MoS2/Ag NPs/NiOx/Al, that further improves light absorption within the monolayer. We used a combination of numerical simulations, analytical models, and experimental optical characterizations to gain insights into the contributions