Blue-emitting and self-assembled thinner perovskite CsPbBr₃ nanoplates: synthesis and formation mechanism

Low dimensional semiconductor nanomaterials show great promise for a variety of applications due to their size-dependent and excellent optoelectronic properties. In this work, we developed a strategy to synthesize uniform and very thin CsPbBr₃ perovskite nanoplates (NPls) by introducing additional metal bromides. The CsPbBr₃ NPls, self-assembled into a face-to-face stacked state, had a thickness of 4.4 nm (equal to only 2 monolayers, 2 MLs) and showed a maximum emission at 437 nm and a narrow FWHM of 14 nm. The formation mechanism of the CsPbBr₃ NPls by adding FeBr₃ was ascribed to the constrained growth of CsPbBr₃ nanocubes when the surface Cs⁺ ions were substituted by the protonated oleylammonium from the byproduct OLA-HBr.