Understanding and controlling interfacial photophysics in perovskite nanocrystal (NC) hybrids is essential for designing next-generation light-harvesting and energy-conversion systems [1]. Metal halide perovskite NCs offer defect-tolerant electronic structures, sizeable oscillator strengths, and tunable excitonic properties that make them ideal donors for driving interfacial energy or charge transfer events. However, the rational design of functional NC–acceptor hybrids requires elucidating how surface chemistry, electronic coupling, and exciton dynamics govern these processes. Herein, we present two complementary works in which CsPbBr₃ NCs are interfaced with molecular acceptors to enable unidirectional transfer of energy or charge to surface-immobilized functional dyes.

In the first approach, CsPbBr₃ NCs are coupled to carboxylated zinc phthalocyanines (ZnPc), yielding a hybrid that mediates an unusual Dexter-type singlet energy transfer (DET) from the NCs to the dye. The strong NC–dye interaction induces, on one hand, the disaggregation of ZnPc molecules on the NC surface—enhancing the inherent photophysical properties of the dye—and, on the other hand, the creation of new surface trap states that open nonradiative pathways, partially reducing energy transfer efficiency. Nonetheless, the resulting CsPbBr₃@ZnPc hybrid operates as an efficient photosensitizer, prolonging triplet-state lifetimes and generating singlet oxygen almost quantitatively upon selective NC excitation [2].

In a second approach, surface-engineering CsPbBr₃ NCs with functional perylenediimides (PDIs) bearing phenyl or phenylpropyl carboxylic spacers produces hybrid systems, that is, NC@PDI-Ph and NC@PDI-PhPr, with well-defined spacer-dependent charge-separation and recombination dynamics. Global target analyses of transient absorption data demonstrate unidirectional electron transfer from the NCs to the PDIs upon excitation of either component. The resulting charge-separated states (CSS) persist on the tens-of-microseconds timescale (34 µs for NC@PDI-Ph and 63 µs for NC@PDI-PhPr), and spacer tuning provides precise control over recombination kinetics [3].

A comprehensive temporal and mechanistic picture of both hybrid systems is established using an arsenal of spectroscopic techniques—steady-state optical spectroscopy, ultrafast, nanosecond, and microsecond transient absorption, time-correlated single-photon counting, and global target analyses—all of which reveal how distinct excitonic components in the NCs drive the observed transfer pathways.

Taken together, these results establish metal halide perovskite NCs as versatile platforms for programming interfacial photophysics, enabling the rational design of hybrid materials for photocatalysis, energy harvesting, and optoelectronic architectures.