Electrochemical Defect-Mediated Thin-Film Growth

Abstract

An electrodeposition technique is described that produces atomically flat epitaxial metal overlayers of quality similar to that obtained by ultrahigh vacuum techniques at elevated temperature. In this approach, a metal of interest such as silver is co-deposited with a reversibly deposited mediator metal. The mediator is periodically deposited and stripped from the surface, and this serves to significantly increase the density of two-dimensional islands of silver atoms, promoting a layer-by-layer thin-film growth mode. In situ scanning tunneling microscopy was used to demonstrate the growth process for the heteroepitaxial system silver/gold (111) with either lead or copper as the mediator.