Mechanical Stabilization of Molecular Junctions by Interaction with Polar Media

The build-up of energy density in nano-scale electronics via inelastic resonant electron transfer is detrimental to chemical bonds’ stability and molecular structure's integrity. This effect may be harnessed for control of the electron (hole) current, but on the other hand, accumulation of excess vibrational heat may lead to bond rupture and breaking of the nano junction. Therefore, finding physical conditions at which these junctions can sustain high-voltage resonant transport is of prime importance for experimental application.<br/>We predict that polar media interacting with the transient charging of the molecule may stabilize junctions under resonant transport. The Polaron-like coulomb interaction of polar media with the charged species is lowering the energetic range for discharging events. In highly-polar solvents, this effect tends to favor cooling transport processes over heating ones, stabilizing the overall charge transfer event. A second effect is brought up by the thermally-induced growth of the number of interacting solvent particle configurations. The widening band of emerging virtual states broadens the possibility windows for charge transfers from (or to) the electrode. This thermal broadening also tends to promote the cooling inelastic charge transfer pathways over the heating ones, overall inducing a temperature + polarity dependent transport-induced cooling effect. These findings are added on top of a temperature-dependent electrode cooling process known from previous studies.