Atomic‐Level Engineering of Au–Ag Nanoclusters Enables Divergent Triplet Emission

Abstract Triplet‐state‐based luminescence holds great promise for next‐generation optoelectronic materials, yet its mechanistic modulation through structural control remains a fundamental challenge for nanomaterials. Here, we present a comparative study of two atomically precise nanoclusters, Au 6 Ag 2 and Au 6 Ag 4 , which feature an identical Au 6 core but differ subtly in Ag atom count and ligand coordination. Despite their structural similarity and triplet dominated emission origin, the results herein reveal that Au 6 Ag 2 exhibits phosphorescence, whereas Au 6 Ag 4 demonstrates dual emission involving both phosphorescence and thermally activated delayed fluorescence (TADF). The contrasting behaviors arise from fine‐tuning the silver contents and organic ligands, which alters photoluminescence nature without modifying the metal core. This work highlights a structure‐driven approach to regulating triplet‐state photoluminescence in metal nanoclusters and offers a blueprint for designing next‐generation triplet‐emissive materials.