Molecular‐based electroactive devices (see image) are constructed using nanocavity architecture and ferrocene‐based molecular structures. The reliable operation of these devices is demonstrated by transport measurements. Two negative differential resistance peaks are observed indicating that both redox and resonance transport processes occur.

A vertical gate symmetrical molecular transistor is demonstrated. It includes self-assembled monolayer of ferrocene molecules chemically bonded to be a flat Au source and Au nanoparticles drain electrodes while gated with the central gate electrode. Using this configuration, we show that negative differential resistance, symmetrical behavior, and rectification effects can be tuned by controlling the gate voltage. The I−V curves shift from symmetric to strongly rectifying over a gate voltage range of a few tenths of volts around a threshold value where the junction behaves symmetrically. This is due to charging of the nanoparticle contact, which modifies the spatial profile of the voltage across the junction, a fact that we have included in a simple theoretical model that explains our experimental results quite well. Our device design affords a new way to fine-tune the rectification of molecular devices in a way that does not necessarily involve the Coulomb charging of the wire.

High-yield fabrication and characterization of a ferrocene-based molecular device is reported. This device, fabricated with the use of modified nanocavity architecture shows very high yield, thus providing a template for exploring the transport properties of molecular junctions. The ferrocene-based devices show multiple negative differential peaks with high reproducibility and temperature stability. We use the multiple arrays to investigate the top-contact effect on the NDR signal at different locations in the wafer.