Single-molecule electrochemical transistors are a type of novel molecular devices in which the tunneling current through the single-molecule junction is modulated by the electrochemical gate, and is considered a promising candidate to be employed in molecular integrated circuits for building the future "molecular computers." Benefiting from the particular interfacial electrical double layer, the current modulation process can be realized through direct orbital gating as well as electrochemical electron transfer driven by electrode potential, thus significantly enriching the functions of the transistor devices. This review focuses on the transfer characteristics and the performance of several typical types of single-molecule electrochemical transistors and the prospects for the fabrication toward integrated devices.

The experimental investigation of intermolecular charge transport in π‐conjugated materials is challenging. Herein, we describe the investigation of charge transport through intermolecular and intramolecular paths in single‐molecule and single‐stacking thiophene junctions by the mechanically controllable break junction (MCBJ) technique. We found that the ability for intermolecular charge transport through different single‐stacking junctions was approximately independent of the molecular structure, which contrasts with the strong length dependence of conductance in single‐molecule junctions with the same building blocks, and the dominant charge‐transport path of molecules with two anchors transited from an intramolecular to an intermolecular path when the degree of conjugation increased. An increase in conjugation further led to higher binding probability owing to the variation in binding energies, as supported by DFT calculations.