Ligand-assisted thickness tailoring of highly luminescent colloidal CH₃NH₃PbX₃ (X = Br and I) perovskite nanoplatelets

Abstract

Quantum size-confined CH₃NH₃PbX₃ (X = Br and I) perovskite nanoplatelets with remarkably high photoluminescence quantum yield (up to 90%) were synthesized by ligand-assisted re-precipitation. Thickness-tunability was realized by varying the oleylamine and oleic acid ligand ratio. This method allows tailoring the nanoplatelet thickness by adjusting the number of unit cell monolayers. Broadly tunable emission wavelengths (450-730 nm) are achieved via the pronounced quantum size effect without anion-halide mixing.