Multicomponent Functional Superlattices Co-Assembled from Shape Anisotropic Lead Halide Perovskite Nanocrystals

Abstract

With the development of new approaches in synthetic chemistry over the last few decades, various colloidal nanocrystals were obtained in the monodisperse form, which, in turn, fostered the extensive research and application possibilities of novel nanomaterials. To this end, self-assembly of colloidal nanocrystals via a bottom-up approach holds great promise for creating metamaterials with programmable functionalities which originate from not only ensemble-average properties but also from diverse synergistic and collective effects, including conductivity enhancement, dipolar interactions, plasmonic couplings as well as collective light emission–superfluorescence. The last was recently shown on the single-component perovskite nanocrystal superlattices. Such peculiar optical properties, together with a high degree of monodispersity, size tunability, and shape anisotropy of perovskite nanocrystals, stimulated research in exploring multicomponent superlattices. Thus, a whole plethora of superlattice types has become accessible, encompassing the superlattices comprised of perovskite nanocubes and spherical, truncated cuboid, or disc-shaped nanocrystals acting as spacers between fluorescent nanocrystals. The superlattices can be fabricated as films on different flat substrates, including at the liquid-air interface, or as spherically confined 3-dimensional supraparticles. A particular interest lies in studying superlattices containing a few light emitter types, wherein promising collective phenomena are expected to emerge. For such systems exemplified on lead perovskite nanocrystal superlattices, we observed the Foster-like energy transfer with accelerated exciton diffusion.