Halogen-Regulated Atomically Thin Two-Dimensional Organic–Inorganic Perovskites with Tunable Fluorescence Emission

Abstract

Organic–inorganic hybrid perovskites have attracted tremendous interest due to their unique properties and promising applications for solar cells and other optoelectronics. Two-dimensional organic–inorganic halide perovskite materials are of essential importance in luminescence fields. The existing methods of regulating optical properties mainly focus on changing the chemical composition and ion doping. Herein, by adopting top-down and dimensional-change strategies, a series of atomically thin organic–inorganic halide perovskites (X-PMA)2PbBr4 (R = 2,3,4 substituted, PMA = benzylamine, X = Cl, Br) have been synthesized and characterized. The material characterizations show that they are structurally similar but slightly different. The optical measurements illustrate that the prepared compounds exhibit not only a broad band but also strong fluorescence emission within 400–800 nm. This feature can be explained by their unique structure, with both substitution of halogen and low dimension. This study enables their promising application for next-generation light-emitting materials and devices and provides an effective strategy for the design of novel optical materials.