Facile room-temperature colloidal synthesis of CsPbBr3 perovskite nanocrystals by the Emulsion-based ligand-assisted reprecipitation approach: Tuning the color-emission by the demulsification process

Although perovskite nanocrystals (PNCs) have established themselves as the future of light-emitting devices and the photovoltaic industry, their synthesis protocols have always been debated. In this study, CsPbBr3 NCs were prepared using an emulsion-based ligand assisted reprecipitation (emulsion LARP) approach. This synthesis approach presented a facile process for preparing CsPbBr3 NCs by removing the hassles and complications experienced in the hot-injection and conventional LARP methods. Emulsion LARP also presented a unique advantage of avoiding the over use of polar solvents, heat-treatments of the precursor solutions, requirement of inert atmosphere, during the synthesis process. Acetone was used as the demulsifier to precipitate NCs from the solution. The introduction of acetone during the synthesis not only improved the photoluminescence intensity of the NCs, but also brought about color-tuning in their emission. By varying the acetone concentration, the color emission was tuned from green to blue. The PNCs prepared by this synthesis protocol demonstrated good photostability under near ultraviolet light exposure and their photoluminescence quantum yield decreased from 64% to 47% over a span of one year.