Synthesis of Novel Stable ZnSe Magic-Sized Clusters and Their Direct Transformation to Quantum Dots.

The inherent instability of magic-size clusters (MSCs), stemming from their ultrasmall dimensions, presents a significant challenge for their synthesis and practical application. This study developed a low-temperature synthesis strategy employing a coordination system based on 1-octadecene selenium (ODESe), diphenylphosphine (DPP) and zinc carboxylate precursors, which successfully produced novel ZnSe clusters with excellent thermal and ligand stability. These robust clusters can serve as precursors for the direct transformation into ZnSe quantum dots (QDs) under mild conditions by simply adding a Se precursors. Notably, the resulting cluster-transformed QDs (6.3 nm) are significantly larger in size than those obtained through the conventional hot-injection method (4.3 nm) at the identical reaction temperature, corresponding to a 19 nm redshift in emission. This work not only establishes a new paradigm for synthesis of stable MSCs but also reveals a non-classical growth regime from robust clusters to large-sized QDs, offering profound insights into the nucleation and growth mechanisms of nanocrystals.