Tuning the emission of copper nanoclusters through bimetallic systems: A comprehensive review on enhanced luminescence for functional ink applications

Abstract Copper nanoclusters (CuNCs) are emerging luminescent materials recognized for their biocompatibility, small size, and low cost. However, their weak photoluminescence (PL) and poor stability limit practical applications. This review discusses recent advances in tuning the emission properties of CuNCs with a specific emphasis on bimetallic approaches involving silver (Ag) and gold (Au). The underlying mechanisms, including ligand‐to‐metal charge transfer (LMCT), ligand‐to‐metal–metal charge transfer (LMMCT), and metal–metal interactions, are also examined, affecting the production of photoluminescent nanoclusters. Bimetallic systems show enhanced PL efficiency, spectral tunability, and mechano‐thermochromic behaviors. This paper introduces new discussions on photoluminescent inks where bimetallic NCs have enabled multicolor and high‐resolution ink formulations. A comparative table of quantum yields and emission properties across these studies is presented to provide insights into their relevance for functional applications such as luminescent ink applications.