Controlled coaggregation pathways of perovskite nanocrystals and supramolecular dye assemblies

Abstract

Abstract High-order aggregates of semiconductor nanocrystals (NCs), known as superlattices, enable the fabrication of exceptional nanomaterials with structure-related physical properties and functionalities. The achievement of a heterogeneous superlattice composed of NCs and functional organic dyes leads to distinctive photophysical properties arising from the interaction between the NCs and dyes, thus activating multicomponent material chemistry. However, a methodology for controlling their heterostructures is yet to be established. Herein, we report a novel supramolecularly controlled coaggregation system involving perovskite NCs and perylene bisimide derivatives (PBIs) that form disorder, low-order, or high-order heterostructures. Their heterostructures were determined by the aggregation conditions of the PBIs (monomers, small aggregates, or large aggregates) before mixing with the NC. Notably, the high-order heterostructure exhibits an exceptional arrangement structure, such as Roman pavement, in which one-dimensionally arranged NCs and one-dimensionally stacked PBIs are alternately arranged at nanometer-scale intervals, as visualized using transmission electron microscopy. Spectroscopic analysis revealed that a high-order heterostructure (heterogeneous superlattice) was formed via an alteration in the π−π stacking interactions between the PBIs on the flat surface of the NC. Moreover, the high-order heterogeneous superlattice exhibited more efficient energy transfer from the NC to the assembled PBIs compared to the low-order heterostructure.