Highly photoluminescent, dense solid films from organic-capped CH3NH3PbBr3 perovskite colloids

Abstract

The preparation of densely-packed films from hybrid lead halide perovskite nanocrystals is not trivial, as during assembly into the solid state both the charge transport and photoluminescence can be substantially altered. The objective of the present study was to retain the pre-engineered confined morphologies of hybrid lead halide perovskite nanocrystals in densely-packed solid films by using short organic ligands. Therefore, the roles of the organic ligands would be to provide stable colloids and a good passivation of the nanoparticle surface, as well as to enable the efficient assembly of the nanoparticles in the solid state. We report here an effective and reproducible process to deposit lead halide perovskite nanoparticle films from colloidal CH₃NH₃PbBr₃ nanoparticles short organic ligands. Remarkably, we demonstrate that nanoparticle solid films with thicknesses of hundreds of nanometres can retain high photoluminescence, with a quantum yield of 80%, and still sustain charge transport.