Exciton-polaritons of hBN/WS₂heterostructure in cavity observed at room temperature

The layer-by-layer buildup of a two-dimensional transition metal dichalcogenide monolayer to form a stack is an important development for these materials, which performs many remarkable properties in the light-matter interaction. Herein, we find clear evidence of exciton-polaritons emerging from WS2/hBN/WS2 heterostructures embedded in a dielectric microcavity under optical pumping. A large Rabi splitting of 15 meV is observed at room temperature, which increases to 25 meV at 5 K. An all-dielectric Fabry-Pérot microcavity provides a simple but effective way to study the room temperature strong coupling between cavity photons and excitons. Our results pave the way for room-temperature polaritonic devices based on quantum-well van der Waals heterostructures.