Engineering highly fluorescent and colloidally stable CsPbBr3 nanocrystals of different shapes using imidazolium-based polysalt ligands

Abstract

We applied a multidentate imidazolium bromide polymer coating to CsPbBr3 perovskite nanocrystals and nanoplatelets to provide passivation of surface vacancies and preservation of the nanocrystal integrity. This ligand is complexed with an additional bromide-based salt, PbBr2 or CoBr2, to overcome the largely damaging effects of etching while imparting colloidal and morphological stability. Photoluminescence quantum yield measurements yielded near-unity for nanocubes and ~ 70 to 80% for nanoplatelets. Structural characterizations showed that application of the ligand or ligand-salt complex does not alter the crystal structure or morphology of the nanocrystals. Graphical abstract: [Figure not available: see fulltext.].