Manipulating the Photoluminescence Pathway in Metal Nanoclusters by Atomic Structural Editing.

Zero-dimensional metal nanoclusters exhibit unique photoluminescence (PL) properties originating from their space confinement, discrete electronic structures and strong metal-ligand interactions. The manipulation of PL pathways through atomic-level structural editing remains a key scientific question. Gold-copper nanoclusters, with their well-defined atomic structures and tunable PL characteristics, offer an ideal platform to investigate this relationship. In this study, two structurally analogous metal nanoclusters, Au18Cu5(SAdm)15 and Au17Cu4(SAdm)15 are synthesized, to explore how atomic-level structural modifications influence the PL mechanism. It is demonstrated that atomic structural editing alters the electronic coupling and the charge distribution, thereby shifting the emission mechanism from surface-state-dominated shell-core relaxation in Au18Cu5(SAdm)15 to core-state-dominated core-shell relaxation in Au17Cu4(SAdm)15. This change effectively modulates PL pathways and affects the directionality of electron transition dipole moments in the nanoclusters, leading to modulated optical absorption properties. These findings deepen the understanding of the structure-property relationships in metal nanoclusters and provide new insights into tailoring their optoelectronic properties through atomic-level compositional control in spatially confined nanostructures.