One-pot scalable synthesis of all-inorganic perovskite nanocrystals with tunable morphology, composition and photoluminescence

Abstract

This study demonstrates a facile and general one-pot synthetic approach for all-inorganic colloidal cesium lead halide (CsPbX₃, X = Cl, Br, I, mixed Cl/Br, Br/I) perovskite nanocrystals (NCs) by directly heating the precursors/solvent/ligands. In contrast to typical routes, these reactions are conducted in open air, requiring neither high temperature dissolution nor a vacuum/inert atmosphere. The composition, shape and size of the as-synthesized NCs can be finely tuned by varying the reaction parameters such as temperature and time, ligand species and precursor halide ratios. CsPbX₃ morphologies may be varied from perovskite nanoplatelets (NPLs) to nanosheets and sphere-like NCs, each with tunable absorption spectra and photoluminescence (PL) emissions. In particular, mixed halide NCs with controllable band gaps and PL emission across the entire visible region have been demonstrated by tuning the precursor halide ratios. The reproducibility and scalability of the present synthetic protocol is elaborated by upscaling the amounts of chemicals and solvents/ligands in a representative synthesis of CsPbBr₃ NPLs. The representative large-scale CsPbBr₃ NPLs exhibit a high PL quantum yield of 73.56%.