Formation of microcavity polaritons in ZnO nanoparticles.

We report the formation of microcavity polaritons in a dielectric microcavity embedded with solution processed ZnO nanoparticles. Evidence of strong coupling between the excitons and cavity photons is demonstrated via anticrossing in the dispersion of the polariton states. At low temperatures (<150K), multiple polariton states arising due to coupling between different excitonic states and the cavity mode is observed. Rabi splitting of ~90 meV is shown to persist even at room temperature in the ZnO – dielectric microcavity.