High-Temperature Ferroelasticity and Photoluminescence in a 2D Monolayer Perovskite Compound: (C5NH8Br)2PbBr4

Anew 2D lead-based organo-inorganic hybrid perovskite (C5NH13Br)(2)PbBr4 (1) (C5NH13Br = 5-bromoamylamine cation) hasbeen reported. Hybrid organic-inorganic perovskites (HOIPs) haveattractedmuch attention due to their excellent properties and easy synthesis.As far as we know, most documented ferroelastics mainly focus on the3D (three-dimensional) perovskites, the 2D monolayer perovskite ferroelasticsare rarely reported before. In this work, we synthesized a 2D lead-basedperovskite (C5NH13Br)(2)PbBr4 (1) (C5NH13Br = 5-bromoamylaminecation) by introducing flexible chain organic cations. The evolutionof ferroelastic domains observed by a polarized light microscope confirmsthat compound 1 undergoes a ferroelastic phase transitionat 392/384 K. In addition, its direct band gap is 2.877 eV. Interestingly,the material emits an attractive blue light (quantum yield 5.06%)under UV light. Three structural descriptors are introduced to quantitativelyanalyze the relationship between structural distortion and the shapeof emission peak. This work provides a way to design multifunctionalperovskite-type materials.

Automated summary

In this study, a new 2D lead-based organo-inorganic hybrid perovskite, (C5NH13Br)(2)PbBr4 (1), was synthesized by introducing flexible chain organic cations. The material exhibits ferroelastic phase transition and emits attractive blue light under UV light. This work provides insights into the design of multifunctional perovskite-type materials.