Near‐Infrared Photoluminescence from Small Copper, Silver, and Gold Nanoparticles

Abstract Here, we report the synthesis and near‐infrared photoluminescence properties of small‐diameter (∼2–3 nm) silver and copper nanoparticles. Periodic trends in nanoparticle quantum yields, observed lifetimes, and emission peak features are studied and compared to each other as well as to previously reported small diameter gold nanoparticles. These trends are distinct from optoelectronic features observed from either their cluster (4–100 atoms) or larger NP (diameter >5 nm) counterparts. Taken together, the successful synthesis and characterization of these materials introduces potential alternatives to small, Au‐based nanoparticles in photoluminescence‐driven applications such as bio‐labeling and sensing, as well as provides additional insight into particle properties at this important size range between molecular and bulk materials.