Near-infrared luminescence AgPd alloy superatomic clusters†

Abstract

Atomically precise superatomic nanoclusters have attracted considerable interest due to their remarkable structures and intriguing photoluminescence properties. Nevertheless, achieving a high photoluminescence quantum yield (PLQY) in the near-infrared (NIR) region of superatomic nanoclusters continues to pose a considerable challenge. Here, we report a novel bimetallic nanocluster prepared utilizing an alloying strategy, formulated as [Ag₁₄Pd(PFBT)₆(TPP)₈](TPP) (abbreviated as Ag₁₄Pd). Notably, this cluster demonstrates a remarkable NIR emission, achieving a PLQY of 15% in the solid state, which is rare for metal nanoclusters. Both experimental and theoretical analyses indicate that Ag₁₄Pd exhibits a characteristic 8-electron superatomic structure with a 1S²1P⁶ electronic shell closure. Furthermore, due to their bright luminescence and exceptional photostability, Ag₁₄Pd clusters hold promising potential for applications as NIR inks for three-dimensional (3D) printing of various objects and models.