A Universal Approach for Controllable Synthesis of n‐Specific Layered 2D Perovskite Nanoplates

Abstract

2D perovskites with chemical formula A′ 2 A n−1 B n X 3n+1 have recently attracted considerable attention due to their tunable optical and electronic properties by varying the chemical composition. While high color‐purity emitting perovskite nanomaterials have been accomplished through changing the halide composition, the preparation of single‐phase, specific n‐layer 2D perovskite nanomaterials is still pending because of the fast nucleation process of nanoparticles. In this study, we demonstrated a facile, rational and efficacious approach to synthesize monodisperse 2D perovskite nanoplates with a designated n number for both lead‐ and tin‐based perovskite through kinetic control. We found that casting carboxylic acid additives in the reaction medium would promote selective formation of the kinetic product, multi‐layer 2D perovskite, in preference to the single layer thermodynamic one. The resulted n‐specific layer 2D perovskites show a trend where decreasing the number of octahedral layers per inorganic sheet leads to an increase of photoluminescence energy, radiative decay rate, and a significant boost in photostability.