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

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 CsPbBr 3 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.