Tuning Facets and Controlling Monodispersity in Organic–Inorganic Hybrid Perovskite FAPbBr₃ Nanocrystals

Lead halide hybrid perovskite nanocrystals are considered as one of the most efficient light-harvesting materials in current research. However, unlike all-inorganic perovskite nanocrystals, the quality optimization and synthetic progress for facet tuning of these hybrid nanocrystals have not moved forward at the same pace. To meet the current demand for high-quality, facet-tuned, and monodisperse nanocrystals, herein, surface A-site cations’ population-controlled facet tuning of FAPbBr3 nanocrystals is reported. Using specific alkylammonium ligands obtained from α-bromo ketones and comparing their concentration with FA+, cubic, dodecahedral, and quasi-spherical shapes of nanocrystals in cubic phase are obtained having monodispersity comparable to that of their best reports. In addition, upon changing of surface ligands, spontaneous formation of self-assembled blue-emitting platelets was also observed. Because of the importance of these materials, these findings will aid the fundamental understanding of formation of hybrid perovskite nanocrystals and also support accelerating their widespread applications.