CsPbBr3 Superstructures with Circularly Polarized Photoluminescence Obtained by the Self‐Assembly and Annealing of Nanoclusters

We report a two‐step approach to fabricate CsPbBr3 superstructures with strongly circularly polarized photoluminescence by self‐assembly of nanoclusters on a substrate, followed by their annealing. In the first step, the nanoclusters self‐assemble upon solvent evaporation, a process that forms mesoscopic superstructures whose geometrical arrangement at the µm‐scale confers them optical chirality. In the second step, mild annealing of such superstructures induces the coalescence of the nanoclusters, accompanied by a continuous red shift of the photoluminescence up to 530 nm, with preservation of the µm‐scale wires bundles and the chiral properties of the sample (glum = 0.1). The successful chirality transfer from the initial nanoclusters assemblies to these final CsPbBr3 superstructures provides a convenient way to obtain circularly polarized emitters.