Metal-halide Perovskite Nanocrystal Superlattice: Self-Assembly and Optical Fingerprints.

Self-assembly of nanocrystals into superlattices is a fascinating process that not only changes geometric morphology, but also creates unique properties that considerably enrich the materials toolbox for new applications. Numerous studies have driven the blossoming of superlattices from various aspects. These include precise control of size and morphology, enhancement of properties, exploitation of functions, integration of the material into miniature devices. The effective synthesis of metal-halide perovskite nanocrystals has advanced research on self-assembly of building blocks into micrometer-sized superlattices. More importantly, these materials exhibit abundant optical features, such as highly coherent superfluorescence, amplified spontaneous laser emission, and adjustable spectral redshift, facilitating basic research and state-of-the-art applications. This review summarizes recent advances in the field of metal-halide perovskite superlattices. We begin with basic packing models and introduce various stacking configurations of superlattices that form the theoretical basis for self-assembled metal-halide perovskite superlattices. We also discuss the potential of multiple capping ligands and highlight their crucial role in superlattice growth, followed by detailed reviews of synthesis and characterization methods. We then consider how these optical features can be distinguished and present contemporary applications. We conclude this review with a list of unanswered questions and an outlook on their potential use in quantum computing and quantum communications to stimulate further research in this area. This article is protected by copyright. All rights reserved.