Blue-Emitting CsPbBr₃ Perovskite Quantum Rods and Their Wide-Area 2D Self-Assembly

A self-digestive process leading to strong blue-emitting nearly monodisperse CsPbBr3 quantum rods in wide-area 2D self-assembly is reported. These are facilitated by aging the presynthesized ultrathin CsPbBr3 nanowires dispersed in appropriate solvent. The time frame was unusual, and the reaction continued for 3–5 days to observe such intriguing patterns. Interfering species such as unreacted precursors, amines, or acids were intentionally minimized with repeated purification for triggering this self-digestive process, which led to the quantum-confined nanorods. Carrying out this reaction in different solvents and in the presence of various additives, the reaction mechanism for such a slow process is established. These nanorods and their large-area self-assembly remained unique in perovskite nanostructures, and the chemistry of the slow process also provided new fundamental insights of the crystallization process of nanorods and their self-assembly.