Effect of edge plasmons on the optical properties of MoS2 monolayer flakes

The electronic edge states of MoS${}_{2}$ nanoparticles are important for the catalytic activity of the particles and could also have potential for photocatalysis. Here, the authors explore computationally optical properties of MoS${}_{2}$ monolayer nanoflakes. These nanostructures show a rich size-dependent optical response below the absorption onset of the infinite monolayer. The authors present a detailed analysis of the emerging optical absorption resonances revealing their edge-state origins. In particular, metallic edge states support localized edge plasmons, and overall, resonances are sensitive to changes in the edge-atom configuration.