Luminescent properties of inorganic perovskite nanocrystals obtained by dimethyl sulfoxide-assisted synthesis in polymer matrices

Ultrasmall spherical perovskite nanocrystals with the composition CsPbBr3, CsPbBr2Cl, CsPbBrCl2, and CsPbCl3 and an average diameter of 3–5 nm were synthesized using a dymethylsulfoxide (DMSO)-assisted synthesis. The obtained nanocrystals were introduced into polystyrene and poly(methyl methacrylate) (PMMA) films during sample formation. It is shown that the polymer matrix significantly affects both the position of the emission maximum and the width of the photoluminescence films of the nanocrystals. In both polystyrene and PMMA films, nanocrystals prepared by the DMSO-assisted synthesis method demonstrated a substantially longer luminescence lifetime compared to nanocrystals synthesized via a ligand-assisted reprecipitation method and introduced into PMMA films. Investigation of PMMA films prepared by spin-coating, using CsPbBr3 and CsPbBr2Cl nanocrystals as model systems, showed that the increased luminescence lifetime observed for nanocrystals obtained via the DMSO-assisted synthesis is caused by their coagulation during the formation of polymer films by solution casting.