Controlled Growth of Colloidal Ultra‐Large ZnS Nanocrystals via Sustained Release of Precursors

Colloidal ZnS nanocrystals (NCs) represent promising ultraviolet functional materials; however, the controlled synthesis of ZnS NCs remains a significant challenge. In this study, we present a slow‐release diffusion synthetic strategy utilizing a single Zn─S source precursor. The Zn─S composite precursor, synthesized from diethylzinc, diphenylphosphine, and trioctylphosphine sulfide, undergoes gradual decomposition in the presence of oleic acid, enabling controlled monomer release. This approach successfully achieves uniform epitaxial growth of ZnS NCs with tunable sizes ranging from 3.8 to 42.3 nm. The growth process, driven by the slow‐release diffusion of this single Zn─S source precursor, exhibits a high growth coefficient of 434 nm 3 /mmol, corresponding to a precursor utilization efficiency of 70%. This work provides a stable and reliable synthetic route for fabricating large‐sized, high‐quality ZnS NCs, thereby expanding their potential applications in ultraviolet optoelectronics.