Solvents in molecular electronics: their role in the conductance of molecular junctions

Conductance measurements in metal/molecule/metal junctions are essential for understanding electron transport at the nanoscale. While previous studies have primarily focused on the intrinsic conductive properties of the molecules within the junction, the role of the solvent environment in which the molecule is deposited has been less explored. The choice of solvent can affect not only the mechanical stability of the molecular junctions but also the interaction between the molecule and the electrodes, thereby influencing the conductance results.

Our studies using STM and STM-BJ reveal that commonly used solvents in molecular electronics, such as benzene, cyclohexane, and toluene, remain adhered to the gold surface, significantly impacting the electronic transport properties of the system. This highlights the importance of understanding the solvent's role in these measurements.

In this study, we evaluate the influence of chloroform and dichloromethane as solvents in conductance measurements of molecular junctions, using mechanically controlled break junction (MCBJ) and scanning tunneling microscopy break junction (STM-BJ) methods, to determine their impact on system stability and conductance.