Layer-by-layer growth of silver on Ag(111) induced by enhanced nucleation: a method study for surfactant-mediated growth

The layer-by-layer growth mode of silver on Ag(111), induced by enhanced nucleation, is reported. It is shown that an artificially high density of nuclei, as observed in studies of surfactant-mediated growth, induces enhanced interlayer mass transport. This growth mode which is usually multilayer (3D), was found to change to layer-by-layer (2D) growth when antimony was used as a surfactant. In a model study on the clean system Ag /Ag(111) (without any surfactant), it was found that two-dimensional layers do grow if the substrate is prepared with an anomalously high density of Ag nuclei. As an enhanced density of nuclei was also observed in presence of Sb, this effect could explain the mechanism for surfactant-induced layer-by-layer growth.