Strong Coupling in a Microcavity LED

Thin films of polyelectrolyte$/J$ aggregate dye bilayers with high absorption coefficient (6 nm thick with $\alpha \approx 1.0\times {10}^6{\mathrm{cm}}^{-1}$) inserted in an optical microcavity enable the cavity quantum electrodynamic strong coupling limit to be reached at room temperature with a coupling strength (Rabi splitting) of $265\pm 15\mathrm{meV}$. By embedding these films in a resonant cavity organic LED structure, we demonstrate the first emissive electrically pumped exciton-polariton device.