Corrosion-induced growth control of lead halide perovskite nanoparticles

Abstract

Ultrasmall CsPbBr3 perovskite nanoparticles (NPs) have gained great attention as a potential blue-cyan emissive material due to their strong quantum confinement effects. However, the preparation of these ultrasmall perovskite NPs remains a challenging task due to their high ionicity and low formation energy. In this study, we propose and demonstrate a corrosion-growth synthesis strategy to achieve size-adjustable, highly-confined CsPbBr3 NPs. Initially, we obtain seed nanoplates (NPLs) through a controlled nucleation process. Subsequently, ethylenediamine (EDA), serving as a polar solvent, controls the corrosion process of unstable NPLs. Interestingly, these corroded NPLs then act as monomers, supplying for the growth of the remaining, stable NPLs. Concurrently, these robust NPLs undergo passivation via the chelation of EDA. By increasing the dosage of EDA, the three dimensions of CsPbBr3 exhibit distinct growth patterns, leading to shape transformation. During the entire process, the absorption and photoluminescence (PL) of the NPLs are predominantly influenced by their thickness, which continues to grow through a modified Ostwald ripening process. Consequently, we achieve thickness-controlled NPs whose PL wavelength can be adjusted from 435 nm to 510 nm, with steps as fine as 1 nm. These NPs exhibit remarkable stability and high PL quantum yield (QYs) due to the passivation by EDA and the strong Mn-ligand interaction.