Carrier dynamics under synergistic interfacial charge and energy transfer in Au–CsPbBr3 nanocrystal heterostructures formed by chemical deposition

Metal-perovskite nanocrystal heterostructures (NHs) offer a useful platform for regulating excited-state dynamics, but the interplay among carrier relaxation, interfacial transfer, and competing recombination pathways remains unclear. Here, Au-CsPbBr3 NHs were constructed by depositing Au nanoparticles (NPs) onto CsPbBr3 nanocrystals, and their carrier dynamics were investigated by transient absorption and time-resolved photoluminescence spectroscopy combined with global analysis. The deposition of Au NPs introduces an additional interfacial relaxation channel and facilitates both charge and energy transfer, leading to ∼50% photoluminescence quenching. Global analysis further shows that the band-edge state population time decreases from 0.84 to 0.60 ps, the band-edge radiative recombination lifetime increases from 218 to 488 ps, and the defect-state radiative decay lifetime decreases from 325 to 246 ps. These results reveal that Au NPs do not merely quench photoluminescence but reconstruct interfacial relaxation and recombination pathways, thereby accelerating carrier cooling, promoting interfacial charge separation, and modulating defect-state emission. Consequently, photogenerated carriers can be transferred to the interface before band-edge recombination and defect-mediated dissipation, increasing the fraction of carriers available for extraction or surface reactions. Photoresponse and electrochemical impedance spectroscopy measurements further support enhanced charge separation and lower interfacial charge-transfer resistance in Au-CsPbBr3 NHs. This work establishes a carrier-dynamics framework for relaxation, transfer, and recombination in Au-CsPbBr3 NHs and provides a mechanistic basis for the rational design of perovskite/metal NHs.