Nontemplate Synthesis of CH₃NH₃PbBr₃ Perovskite Nanoparticles

TLDR

No free, nanometer‑sized CH₃NH₃PbBr₃ perovskite nanoparticles have been reported in the literature. The study aims to synthesize 6‑nm CH₃NH₃PbBr₃ nanoparticles using a rapid, template‑free approach. The synthesis employs an ammonium bromide with a medium‑chain alkyl group to stabilize the nanoparticles in a broad range of organic solvents. The resulting nanoparticles remain stable in solid state and concentrated solutions for over three months, can be spin‑coated into uniform thin films, and emit narrow‑band visible light with a 20 % quantum yield, making them promising for optoelectronic devices.

Abstract

To date, there is no example in the literature of free, nanometer-sized, organolead halide CH3NH3PbBr3 perovskites. We report here the preparation of 6 nm-sized nanoparticles of this type by a simple and fast method based on the use of an ammonium bromide with a medium-sized chain that keeps the nanoparticles dispersed in a wide range of organic solvents. These nanoparticles can be maintained stable in the solid state as well as in concentrated solutions for more than three months, without requiring a mesoporous material. This makes it possible to prepare homogeneous thin films of these nanoparticles by spin-coating on a quartz substrate. Both the colloidal solution and the thin film emit light within a narrow bandwidth of the visible spectrum and with a high quantum yield (ca. 20%); this could be advantageous in the design of optoelectronic devices.