Perovskite nanocrystals now available with 12 and 26 facets

A novel synthesis procedure can produce highly uniform luminescent perovskite nanocrystals with uncommon shapes and surface morphologies. The finding broadens the range of strategies that can be used for tuning the optical and photonic properties of these materials, which are widely studied for use in solar cells, light-emitting diodes, and electronic displays. In the past few years, many research groups have devised methods for improving the chemical stability and boosting the luminescence of lead halide nanocrystals that have the perovskite structure and stoichiometry. Invariably, these materials are six-sided crystals (cubes or platelets) in which the atoms in the faces, or facets, line up in one or two standard geometries. By using an α-halo ketone as the halide precursor, Suman Bera, Rakesh Kumar Behera, and Narayan Pradhan of the Indian Association for the Cultivation of Science have now come up with a simple way to make highly luminescent 12- and 26-sided cesium-lead-bromide nanocrystals with nonstandard facets (J. Am. Chem. Soc. 2020, DOI: 10.1021/jacs.0c10688). The researchers note that unlike other syntheses, which form primary ammonium ions in the reaction mixture, their method generates tertiary ammonium ions that help stabilize the unusual facets and crystal shapes.