Simulation of Colloidal Silver Nanoparticle Formation from a Precursor Complex

The formation of oleylamine-stabilized colloidal silver nanoparticles (Ag-NPs), which are the most promising metal NP inks for printed electronics, was modeled and simulated to investigate the shell structure of the oleylamine coating of the Ag-NPs. Our simulation results showed that Ag-NP growth occurred by the coalescence of silver clusters. We also found that the oleylamine shell structure surrounding the Ag-NPs was not the commonly assumed radially extending structure with a single amine group adsorbed to the silver surface but rather a partially lying-down structure with multiple adsorbed groups. The latter structure results in a thinner shell and contains fewer stabilizing agents than the former, which may contribute to the low-temperature sintering characteristics of Ag-NP inks.