Velocity field distribution control in antisolvent flow realizing highly stable and efficient perovskite nanocrystals.

A stable velocity field distribution of antisolvent flow enables the synthesis of efficient FAPbI 3 perovskite NCs with achieved ∼100 % PLQY and low defect density (∼0.2 cm−3 per NCs) without applying functional additives or further encapsulation. The NCs show incredible reproducibility and remarkable stability of maintaining over 80 % PLQY in an ultra-diluted concentration of 9.3×10-6 mg/mL. [Display omitted] Achieving highly stable and efficient perovskite nanocrystals (NCs) without applying functional additives or encapsulation, particularly sustaining the stability in ultra-dilute solution, is still a formidable challenge. Here, we show the FAPbI 3 perovskite NCs with achieved ∼100 % photoluminescence quantum yield (PLQY) and low defect density (∼0.2 cm−3 per NCs), which is obtained by controlling the velocity field distribution of antisolvent flow in ligand-assisted reprecipitation process. The NCs show incredible reproducibility with narrow deviation of PLQY and linewidth between batch by batch, as well as remarkable stability of maintaining over 80 % PLQY, either in an ultra-diluted solution (9.3 × 10-6 mg/mL), or storing in ambient condition after 90 days with concentration of 0.09 mg/mL. The results in this work demonstrate the interplay of fluid mechanics and crystallization kinetics of perovskite, which pioneers a novel and unprecedent understanding for improving the stability of perovskite NCs for efficient quantum light source. [ABSTRACT FROM AUTHOR]