Photophysics of Two-Dimensional Semiconducting Organic-Inorganic Metal-Halide Perovskites

TL;DR

This review explores how organic cations influence the structural and optical properties of 2D hybrid perovskites, emphasizing their complex photophysical behavior and potential for future applications.

Contribution

It provides a comprehensive analysis of the role of organic cations in 2DHPs, linking lattice distortions to optical phenomena and excitonic structures.

Findings

Cation-induced lattice distortion affects optical properties.

Discrete excitonic structures vary with temperature and cation type.

Hot exciton photoluminescence depends on the organic cation.

Abstract

2D organic-inorganic hybrid perovskites (2DHPs) consist of alternating anionic metal-halide and cationic organic layers. They have widely tunable structural and optical properties. We review the role of the organic cation in defining the structural and optical properties of 2DHPs through example lead iodide 2DHPs. Even though excitons reside in the metal halide layers, the organic and inorganic frameworks cannot be separated-they must be considered as a single unit to fully understand the photophysics of 2DHPs. We correlate cation-induced distortion and disorder in the inorganic lattice with the resulting optical properties. We also discuss the role of the cation in creating and altering the discrete excitonic structure that appears at cryogenic temperatures in some 2DHPs, including the cation-dependent presence of hot exciton photoluminescence. We conclude our review with an outlook for 2DHPs, highlighting existing gaps in fundamental knowledge as well as potential future applications.