Gated-controlled rectification of a self-assembled monolayer-based transistor

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

Vertically Stacked Molecular Junctions: Toward a Three-Dimensional Multifunctional Molecular Circuit

We demonstrate a new method for the construction of three-dimensional vertically stacked molecular junctions. Our approach involves the sequential formation of encapsulated metal−self-assembled monolayer−metal junctions in a three-dimensional configuration, thus forming a molecular circuit. The molecular circuit is constructed at low temperature while utilizing novel process methods in order to minimize possible damage to the molecular layers. We demonstrate this concept by introducing redox-based molecules and proteins into a two-floor molecular circuit and evaluating their electronic properties separately.We show that the electronic molecular “fingerprints” were preserved during the process, and it could be successfully adopted for different types of molecular systems