RESUMO
Monolayer transition metal dichalcogenides integrated in optical microcavities host exciton-polaritons as a hallmark of the strong light-matter coupling regime. Analogous concepts for hybrid light-matter systems employing spatially indirect excitons with a permanent electric dipole moment in heterobilayer crystals promise realizations of exciton-polariton gases and condensates with inherent dipolar interactions. Here, we implement cavity-control of interlayer excitons in vertical MoSe2-WSe2 heterostructures. Our experiments demonstrate the Purcell effect for heterobilayer emission in cavity-modified photonic environments, and quantify the light-matter coupling strength of interlayer excitons. The results will facilitate further developments of dipolar exciton-polariton gases and condensates in hybrid cavity - van der Waals heterostructure systems.
RESUMO
Colloidal semiconductor nanoplatelets exhibit quantum size effects due to their thickness of only a few monolayers, together with strong optical band-edge transitions facilitated by large lateral extensions. In this article, we demonstrate room temperature strong coupling of the light and heavy hole exciton transitions of CdSe nanoplatelets with the photonic modes of an open planar microcavity. Vacuum Rabi splittings of 66 ± 1 meV and 58 ± 1 meV are observed for the heavy and light hole excitons, respectively, together with a polariton-mediated hybridization of both transitions. By measuring the concentration of platelets in the film, we compute the transition dipole moment of a nanoplatelet exciton to be µ = (575 ± 110) D. The large oscillator strength and fluorescence quantum yield of semiconductor nanoplatelets provide a perspective toward novel photonic devices by combining polaritonic and spinoptronic effects.
