Hierarchical Coaggregation of Perovskite Nanocrystals and Dye Supramolecular Aggregates into a High‐Order Heterostructure

Abstract A high‐order heterogeneous nanostructure (heterostructure) composed of semiconductor nanocrystals (NCs) and organic dye supramolecular aggregates can exhibit distinctive photophysical properties arising from the interaction between them and can activate multicomponent materials chemistry. Herein, the study demonstrates a hierarchical coaggregation pathway guiding a high‐order heterostructure composed of a cubic‐shaped perovskite NC and perylene bisimide derivative (PBI) aggregates. The final morphologies in their coaggregation are determined by the aggregation levels of PBI before mixing with NCs. While mixing of NCs with monomers or aged fibrous aggregates of PBI results in the formation of low‐order or phase‐separated coaggregates, respectively, a coaggregation of the NC with unaged sheet‐like aggregates of PBI afforded the high‐order heterostructure. In this heterostructure, one‐dimensionally arranged NC and aggregated PBI are alternately connected at several nanometer‐scale intervals, like Roman pavement. Moreover, photoluminescence spectra and time‐resolved measurements at single coaggregate levels indicate that the high‐order heterostructure exhibited more efficient fluorescence resonance energy transfer from the NC to PBI aggregates compared to the phase‐separated coaggregates.