Strong exciton-photon coupling in a microcavity containing layered perovskite semiconductors

The authors have realized a Pérot-Fabry microcavity containing a two-dimensional layered perovskite-type semiconductor, ${({\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{C}}_2{\mathrm{H}}_4–\mathrm{N}{\mathrm{H}}_3)}_2\mathrm{Pb}{\mathrm{I}}_4$ , between a dielectric mirror and a metallic mirror. A strong coupling regime between the perovskite exciton and the confined photon mode has been evidenced at room temperature from angular-resolved reflectivity experiments. An anticrossing of $140\mathrm{meV}$ is observed between the excitonic and cavity modes. ${({\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{C}}_2{\mathrm{H}}_4–\mathrm{N}{\mathrm{H}}_3)}_2\mathrm{Pb}{\mathrm{I}}_4$ having a self-organized multiple quantum well structure, they have determined the oscillator strength per quantum well of this structure: $4\times {10}^{13}{\mathrm{cm}}^{-2}$ , which is one order of magnitude higher than in conventional inorganic quantum wells.