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

Abstract Surface chemistry and quantum confinement in nanocrystals (NCs) can modulate the energy transfer efficiency between lead halide perovskite (LHP) NCs and acceptor molecules in hybrid assemblies. It is demonstrated here that colloidal CsPbBr₃ NCs capped with the oleic acid/oleylamine ligand pair act 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 consistent with the strong binding of the BODIPY to the NC surface via the carboxylate group, as is evidenced by nuclear magnetic resonance (NMR) and Fourier‐transform infrared (FTIR) spectroscopies. A thorough analysis suggests a Förster resonance energy transfer (FRET) mechanism from the perovskite to the acceptor dye. These results provide a better understanding of the underlying interaction in perovskite−organic chromophore nanohybrids and can be employed in the design of novel harvesting assemblies.