  Understanding of charge transport mechanisms in nanoscale structures is
essential for the development of molecular electronic devices. Charge transport
through 1D molecular systems connected between two contacts is influenced by
several parameters such as the electronic structure of the molecule and the
presence of disorder and defects. In this work, we have modeled 1D molecular
wires connected between electrodes and systematically investigated the
influence of both soliton formation and the presence of defects on properties
such as the conductance and the density of states. Our numerical calculations
have shown that the transport properties are highly sensitive to the position
of both solitons and defects. Interestingly, the introduction of a single
defect in the molecular wire which divides it into two fragments both
consisting of an odd number of sites creates a new conduction channel in the
center of the band gap resulting in higher zero-bias conductance than for
defect free systems. This phenomenon suggests alternative routes toward
engineering molecular wires with enhanced conductance.
