Room-temperature polaron-mediated polariton nonlinearity in MAPbBr3 perovskites

TL;DR

This study demonstrates that MAPbBr3 perovskites support stable, strongly interacting exciton-polaritons at room temperature due to polaron effects, enabling enhanced nonlinear optical responses for practical photonic applications.

Contribution

It reveals that polaron effects in hybrid perovskites significantly enhance room-temperature polariton nonlinearity, overcoming limitations of traditional semiconductors.

Findings

Large nonlinear blueshifts observed under femtosecond excitation

Exciton-polaron-polaritons remain stable and strongly interacting at room temperature

Polaron effects mediate inter-particle interactions, enhancing nonlinearity

Abstract

Systems supporting exciton-polaritons represent solid-state optical platforms with a strong built-in optical nonlinearity provided by exciton-exciton interactions. In conventional semiconductors with hydrogen-like excitons the nonlinearity rate demonstrates the inverse scaling with the binding energy. This makes excitons stable at room temperatures weakly interacting, which obviously limits the possibilities of practical applications of the corresponding materials for nonlinear photonics. We demonstrate experimentally and theoretically, that these limitations can be substantially softened in hybrid perovskites, such as MAPbBr3 due to the crucial role of the polaron effects mediating the inter-particle interactions. The resulting exciton-polaron-polaritons remain both stable and strongly interacting at room temperature, which is confirmed by large nonlinear blueshifts of lower polariton branch energy under resonant femtosecond laser pulse excitation. Our findings open novel perspectives for the management of the exciton-polariton nonlinearities in ambient conditions.