Interphase: On Nanofabrication and Electrical Double Layer Dynamics with Electrochemical Scanning Probes

This thesis aims to measure and control behavior of ions in solution near a charged, or electrified, surface. Such electrochemical systems are found everywhere, ranging from biological to industrial processes, and can be greatly affected by small changes at the boundary between the solid and the liquid. A better understanding of the dynamic processes occurring at the electrified interface is therefore of great interest for many applications. In particular, the main focus of this thesis lies on forcing ions to deposit locally with nanoscale precision under influence of an applied potential, ultimately providing a path to the free-form writing of 3-dimensional functional materials. The bulk of the presented experiments make use of a sharp probe, either an atomic force microscope or a scanning tunneling microscope, to both initiate the local deposition of metals and inspect the resulting structures, providing information on the underlying process. We present two novel ways of direct nanoscale electrodeposition using electrochemical scanning probes, and investigate the growth mechanisms. In the final chapters we expand the range of electrochemical phenomena under investigation from deposition reactions; to the potential-controlled state of the surface; and finally to the behavior of devices tailored to harness excess charge in the solution, near the interface