Low temperature synthesis of ultra-green luminescent colloidal FAPbBr(3) perovskite nanocrystals

According to the updated recommendation for displays standard (Rec. 2020), ultrapure green emitters with a narrow emission (below 25 nm) in the 525-535 nm spectral range are desired. However, finding an emitter material that can meet such requirements, is still challenging. To this purpose, organic-inorganic halide perovskites nanocrystals have been considered as promising high-color purity light emitters at a lower cost, that overcome the issues associated with conventional emitters. Herein, to reach these standards simultaneously, we have synthesized Formamidinium lead bromide perovskite nanocrystals (NCs) at room temperature by ligand-assisted reprecipitation (LARP). The obtained FAPbBr3 NCs coated with oleic acid and oleylamine show an average size of about 20 nm. FAPbBr3 NCs dispersions in hexane exhibited bright photoluminescence with a high quantum yield (74%). The color coordinates on CIE 1931 are (0.2, 0.75), with a corresponding strong green emission at 533 nm. The emission is characterized by an ultranarrow full width at half-maximum (FWHM = 22 nm), and long radiative lifetimes (?82 ns). The synthesized FAPbBr3 NCs present ideal features toward solution-processable ultrapure green emitters.