A permanent, stable, and simple top-contact for molecular electronics on Si: Pb evaporated on organic monolayers

We show that thermally evaporated lead (Pb) preserves the electronic properties of organic monolayers on Si and the surface passivation of the Si surface itself. The obtained current-voltage characteristics are in accordance with results from the well-established hanging mercury drop method and preserve both the molecule-induced dipolar effect and length-attenuation of current. We rationalize our findings by the lack of interaction between the Pb and the Si substrate. Our method is fast, scalable, compatible to standard semiconductor processing, and can help to spur the large-scale utilization of silicon-organic hybrid electronics.