Highly stable mixed halide perovskite quantum dots synthesized in the presence of fluorous ligands

Abstract

AbstractThis work probes the potential of fluorous fatty acids as stabilizing ligands in the synthesis of mixed halide perovskite quantum dots (MHP QDs). Traditionally, MHP QDs are synthesized in the presence of oleic acid (OA) and oleyl amine (OAm). Here fluorous fatty acids have been used along with OA and OAm to yield MHP QDs with higher stability. Increased fractions of fluorous molecules in reaction mixture require the process to be carried out at a higher temperature due to the distinctive temperature‐dependent mixing behavior of perfluorinated ligands. Best of fluorous acid functionalized QDs in solution showed a 9% decrease in their photoluminescence quantum yield (PLQY) over 30 days compared to 27% in those without. The composition of fluorous fatty acids during synthesis influences the size, form and optical properties of MHP QDs. Further in situ addition of non‐carboxylic acid fluorous ligands (thiols) are also shown to the give similar improvements in stability and optical properties of MHP QDs. The in situ fluorous ligand functionalization studied in this work presents a new method to improve the stability of MHP‐QD while providing a thermally controlled handle to tune the structure of nanoparticle films.