Theory of nonlinear excitonic response of hybrid organic perovskites in the regime of strong light-matter coupling

TL;DR

This paper investigates the nonlinear optical behavior of layered organic perovskites in microcavities under strong light-matter coupling, highlighting their unique excitonic interactions and large polariton blueshifts compared to traditional semiconductors.

Contribution

It provides a quantitative analysis of how multilayer structure influences excitonic nonlinearity and polariton dynamics in hybrid organic perovskites.

Findings

Significant increase in exciton binding energy and Rabi splitting due to multilayer structure.

Dominant Rabi splitting quench effect in nonlinear response.

Achieved extremely large polariton blueshifts of about 50 meV.

Abstract

We present a quantitative study of the nonlinear optical response of layered perovskites placed inside planar photonic microcavities in the regime of strong light matter coupling, when excitonic and photonic modes hybridize and give rise to cavity polaritons. Two sources of nonlinearity are specified, the saturation of the excitonic transition with increase of the optical pump and Coulomb interaction between the excitons. It is demonstrated, that peculiar form of the interaction potential, specific to multilayer structure of organic perovskites, is responsible for substantial increase of the exciton binding energy and Rabi splitting with respect to conventional semiconductor systems. This results in dominant contribution of the Rabi splitting quench effect in the nonlinear optical response. Moreover, due to the tightly bound character of excitons, the density of Mott transition is essentially higher, allowing to reach extremely large polariton blueshifts of about 50 meV, which is order of magnitude higher than in conventional semiconductors.