Amplification Of Strong Exiton-photon Coupling Based On Surface Plasmon In A Hybridized Inorganic-Organic Perovskite NanoWire-Metal Film-Perovskite NanoWire Structure

The strong exciton-photon coupling in the perovskite nanowire cavity is an ideal material for the preparation of room temperature polariton due to its high Rabi splitting energy and exciton binding energy.Nevertheless,new methods are explored to enhance the exciton-photon coupling strength in order to maintain the exciton-photon coherence.Surface plasmon can enhance exciton-photon coupling by reducing the effective mode volume and increasing the intensity of the local electric field.Our work explores a strong exciton-photon coupling in a sandwich hybrid structure consisting of inorganic-organic perovskite nanowires,silicon dioxide（SiO₂）films,and silver（Ag）films.With the introduction of surface plasmons,the hybridization mode can reduce the dissipation of the whole system,thus enhancing the exciton-photon coupling.Through calculation,it is found that the thickness of SiO₂ and Ag films can affect the coupling strength.When the optimal thickness of SiO₂ at 5 nm and Ag at 30 nm is reached,the rabi splitting energy can reach 319 meV,while the rabi splitting energy is only 270 meV without Ag film.In addition,there is a linear relationship between the rabi splitting energy and the thickness of SiO₂ films.However,it has a nonlinear relationship with the thickness of Ag film,because the effective exponential imaginary part of the hybrid mode has a nonlinear relationship with the thickness of Ag film.We replaced the protective layer in the middle with the dielectric layer with adjustable refractive index,and found that the higher the refractive index,the greater the coupling strength.In the choice of metal film,compared with the gold film and silver film,found that the loss of gold film is greater.On the basis of exploring the enhancement of the exciton-photon coupling intensity in perovskite by surface plasmons,we also modulated the nonlinear Fano resonance formed by surface plasmons cavity and the biexcitons in perovskite nanosheets.Through FDTD simulation and Fano resonance formula fitting,we found that the smaller the thickness of SiO₂ film,the smaller the thickness of silver film,and the larger the radius of silver nanowire,the higher the transmittance of the formant.Our conclusions about surface plasmon how to enhance exciton-photon coupling strength in hybrid perovskite and how surface plasmon cavity and biexciton of the perovskite nanoplatelets form the nonlinear Fano resonance has carried on the detailed regulation,our results for the design of demonstration and ultra-low threshold laser optical device have potential application prospect.