Concentration Dependent Modulation in Optoelectronic Traits of Self‐Collated CsPbBr 3 Perovskites

Abstract Self‐collation of perovskite nanocrystals into superstructures of larger length scales has been growing in research interest due to their dramatically enhanced performance in various nano‐devices, modulating their optical and electrical traits. Herein, the unique concentration‐dependent self‐assembly of phenethylamine (PEA)‐capped CsPbBr 3 (PCPB) perovskites spanning a size range of nano to micron level without structural phase alteration is infered. By optimizing various synthetic parameters like PEA amount, and solvents, the self‐coalescence in PCPB crystal growth is controlled. Furthermore, the highest‐concentrated PCPB (C5) has improved the charge transfer (CT) efficiency to 1,4‐Napthoquinone (NPQ), corroborated with stronger binding between C5 and NPQ, compared to the lowest‐concentrated PCPB (C1). Incorporating NPQ into such concentration‐dependent PCPB enhances their local conductance unveiling the CT‐induced current rise, while the detrimental insulating property of PEA molecules reduces the conductance in C5 compared to C1. These outcomes offer a foundation for tailoring the properties of self‐assembled perovskites for optoelectronic devices and energy conversion technologies.