Electrochemical defect-mediated thin-film growth

An electrodeposition technique is described that produces atomically flat e pitaxial metal overlayers of quality similar to that obtained by ultrahigh vacuum techniques at elevated temperature. In this approach. a metal of int erest such as silver is co-deposited with a reversibly deposited mediator m etal. The mediator is periodically deposited and stripped from the surface, and this serves to significantly increase the density of two-dimensional i slands of silver atoms, promoting a layer-by-layer thin-film growth mode. I n situ scanning tunneling microscopy was used to demonstrate the growth pro cess for the heteroepitaxial system silver/gold (111) with either Lead or c opper as the mediator.