Adsorption of Si on Cu(100) and (111) surfaces

Employing the density-functional theory within the generalized gradient approximation, we investigate the interaction between atomic Si and the Cu(100) and (111) surfaces. Various structures of on-surface adsorption as well as surface-substitutional adsorption for a wide range of Si coverage are considered. Our results show that both Cu(100) and (111) surfaces are active for adsorption of Si. The c(2 x 2)-Si/Cu(100) surface alloy is energetically favourable for a large range of Si chemical potential while c(2 x 2)-Si/Cu(111) is energetically favourable only under Si rich conditions.