Theoretical study on amplifying strong exciton–photon coupling based on surface plasmon in a hybridized perovskite nanowire-metal film-perovskite nanowire structure

We theoretically report a strong light–matter interaction in a sandwich structure composed of hybridized inorganic–organic perovskite nanowires, silica (SiO 2 ) films and a silver (Ag) film. Surface plasmon effectively enhances the strong exciton–photon coupling strength of perovskite nanowires, which depends on reduction of effective mode volume and local field enhancement. By calculation, we find that the thicknesses of SiO 2 and Ag films can affect the coupling strength. With the suitable thickness of SiO 2 (5 nm) and Ag (30 nm) films, Rabi splitting can reach 319 meV, while without an Ag film Rabi splitting is only 270 meV. Furthermore, Rabi splitting shows a negative correlation with SiO 2 film thickness within a limited range. Still, it has a nonlinear relation with Ag film thickness because the imaginary part of the effective index for the hybridized mode shows a nonlinear relation with Ag film thickness. Our structure provides suitable parameters for the experiment and has potential application in nano-lasers.