Room-Temperature Strong Coupling between CdSe Nanoplatelets and a Metal-DBR Fabry–Pérot Cavity

Abstract

We present the generation of exciton-polaritons in CdSe nanoplatelets (NPLs) at room temperature in a metal-dielectric hybrid cavity. The optical cavity is packed with NPLs devoid of any spacer, allowing a larger population of emitters to couple to the cavity. The NPL-filled cavity system shows a Rabi splitting of 74.5 meV compared to the previously obtained 41.5 meV Rabi splitting with an NPL-in-PMMA cavity at room temperature. Angle-resolved reflectance and photoluminescence measurements are performed to explore the polariton photophysics by varying the cavity-exciton detuning and temperature. The role of dark states as a reservoir in redistributing polariton populations is also investigated. Mixed quantum-classical dynamics calculations are performed to model the polariton system wherein the theoretical simulations agree with the experimental observations, providing a fundamental understanding of the polariton dynamics within the NPL-cavity hybrid system. These room-temperature exciton-polaritons have the potential to unlock new chemical reaction pathways as well as pave the way for developing cutting-edge quantum technologies.

Dark State Concentration Dependent Emission and Dynamics of CdSe Nanoplatelet Exciton-Polaritons

“…Alternatively, a means to directly access the dark state manifold is provided by off-resonant pumping, early implementations of which have involved cavity-embedded J-aggregates. 29,30 Recently, off-resonant pumping has been applied to cavity-embedded cadmium selenide (CdSe) nanoplatelets (NPLs), 31,32 where subsequent detection of emission unveiled the importance of phonons in mediating polariton transitions. 31 These advances notwithstanding, the systematic study of dark states remains in its infancy.…”

Dark State Concentration Dependent Emission and Dynamics of CdSe Nanoplatelet Exciton-Polaritons

“…Alternatively, a means to directly access the dark state manifold is provided by off-resonant pumping, early implementations of which have involved cavityembedded J-aggregates. 29,30 Recently, off-resonant pumping has been applied to cavity-embedded cadmium selenide (CdSe) nanoplatelets (NPLs), 31,32 where subsequent detection of emission unveiled the importance of phonons in mediating polariton transitions. 31 These advances notwithstanding, the systematic study of dark states remains in its infancy.…”