Deterministic Areal Enhancement of Interlayer Exciton Emission by a Plasmonic Lattice on Mirror.

The emergence of interlayer excitons (IX) in atomically thin heterostructures of transition metal dichalcogenides (TMDCs) has drawn great attention due to their unique and exotic optical and optoelectronic properties. Because of the spatially indirect nature of IX, its oscillator strength is 2 orders of magnitude smaller than that of the intralayer excitons, resulting in a relatively low photoluminescence (PL) efficiency. Here, we achieve the PL enhancement of IX by more than 2 orders of magnitude across the entire heterostructure area with a plasmonic lattice on mirror (PLoM) structure.