Lead Halide Perovskite‐Based Nanoheterostructures: Design, Properties, and Applications

Heterostructures have driven the commercialization of classical quantum dots by substantially enhancing their optoelectronic performance and stability. Lead halide perovskite nanocrystals demonstrate excellent optoelectronic properties while suffering from structural degradation under stresses like moisture, heat, oxygen, and light. Consequently, the implementation of heterostructure design strategies in perovskite nanocrystals remains an active area of research. This review provides a comprehensive overview of recent advances in perovskite‐based nanoheterostructures, focusing on synthetic strategies, growth mechanisms, crystallographic relationships, optical properties, and their implementation in various optoelectronic devices. We emphasize the concept of epitaxial interfaces and the challenges associated with epitaxial growth in perovskite nanocrystals. Nanoheterostructures formed by integrating perovskite nanocrystals with metal chalcogenides, lead chalcohalides, metal halides, oxides, perovskite derivatives, and metallic nanoparticles are considered. The interfacial band alignment, facet‐selective growth, and their influence on charge carrier dynamics, photoluminescence properties and environmental stability in epitaxial perovskite nanoheterostructures are discussed. These advances have enabled demonstrations of perovskite nanoheterostructures in devices including solar cells, light‐emitting diodes, photodetectors, and photocatalytic systems. Finally, the Review explores the possibilities for expanding the library of perovskite‐based nanoheterostructures, including strategies to enable multifacet heteronucleation, utilization of common sublattices for epitaxial coupling, and the development of anisotropic architectures, such as nanorod heterostructures.