Singlet Sensitization of a BODIPY Rotor Triggered by Marriage with Perovskite Nanocrystals

Surface chemistry and quantum confinement in nanocrystals (NCs) canmodulate the energy transfer efficiency between lead halide perovskite (LHP)NCs and acceptor molecules in hybrid assemblies. It is demonstrated herethat colloidal CsPbBr 3 NCs capped with the oleic acid/oleylamine ligand pairact as a good singlet sensitizer of meso-(4-carboxyphenyl) BODIPY dye(C-BPY). The energy transfer efficiency of ≈85% at 1 × 10−6 m is consistentwith the strong binding of the BODIPY to the NC surface via the carboxylategroup, as is evidenced by nuclear magnetic resonance (NMR) andFourier-transform infrared (FTIR) spectroscopies. A thorough analysissuggests a Förster resonance energy transfer (FRET) mechanism from theperovskite to the acceptor dye. These results provide a better understandingof the underlying interaction in perovskite−organic chromophore nanohybridsand can be employed in the design of novel harvesting assemblies.