Electrochemical Metallization of Molecular Adlayers

Electrochemical metallization of molecular adlayers allows to sandwich a group of molecules between a metallic substrate and a metal nanoisland or nanocluster through a wet process not requiring expensive vacuum equipment and with precise control through the electrode potential. This metal-molecule-metal sandwiches could provide a simple means to integrate molecules in electronic circuits, or to explore effects arising due to quantum confinement of electrons due to the reduced dimensions of the islands or clusters deposited on the adlayer. Although initial attempts resulted in penetration through the adlayer and direct deposition on the metal substrate, the development 14 years ago of a two-step technique involving pre-adsorption of the target cation on the SAM prior to its reduction in an electrolyte not containing that cation opened a whole new range of possibilities. In this brief review we discuss the development and recent advances in the implementation of this technique, and briefly discuss the outlook for future work.