Lin J.-TChen D.-GWu C.-HHsu C.-SChien C.-YChen H.-MChou P.-TCHING-WEN CHIUHAO MING CHENPI-TAI CHOU2021-08-032021-08-03202114337851https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101851738&doi=10.1002%2fanie.202016140&partnerID=40&md5=e48d493e6127ff5bdfe127cc5574eec7https://scholars.lib.ntu.edu.tw/handle/123456789/5757142D perovskites with chemical formula A′2An?1BnX3n+1 have recently attracted considerable attention due to their tunable optical and electronic properties, which can be attained 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. We demonstrate a facile, rational and efficacious approach to synthesizing single-phase 2D perovskite nanoplates with a designated n number for both lead- and tin-based perovskites through kinetic control. Casting carboxylic acid additives in the reaction medium promotes selective formation of the kinetic product—multilayer 2D perovskite—in preference to the single-layer thermodynamic product. For the n-specific layered 2D perovskites, 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. ? 2021 Wiley-VCH GmbHAdditives; Electronic properties; Nanostructured materials; Nanostructures; Chemical compositions; Controllable synthesis; Optical and electronic properties; Photoluminescence energy; Radiative decay rates; Selective formation; Thermodynamic products; Universal approach; Perovskitejournal article10.1002/anie.202016140334037492-s2.0-85101851738