Fabrication of nanogap electrodes using electrodeposition process

Laterally-enhanced growth of Au using electrochemical deposition from an electrode onto SiO₂ surface modified with organic molecules for fabrication of nanogap electrodes was investigated. After modifying the SiO ₂ surface with self-assembled monolayers (SAMs) or dendrimer, electrodeposition was carried out and the enhanced lateral deposition was observed from the edge of Au electrode onto the SiO₂ surface. In order to analyze the surface states modified with SAMs or dendrimer, X-ray photoelectron spectroscopy (XPS) were conducted and the existence of the organic molecules and Au ions on the SiO₂ surface was confirmed. It was suggested that the enhanced lateral deposition was induced by the adsorbed Au ions. Furthermore, we tried to measure the electrical property of phthalocyanine molecular wire using the gap electrodes. In order to improve the contact state between the wire and the electrodes, electrodeposition was applied. As a result, improvement of contact state was observed from Current-Voltage characterization.