Disorder-Induced Rectification in a Molecular System

In this work, We study on the electron transport of an ensemble of coupled sites that simulates an array of quantum dots or a molecular system. By using the Green’s function technique, we calculate current and shot noise for linear and disordered site arrays. While in the linear case the characteristic I–V curve reveals no current rectification, in the disordered configurations a robust rectification is found, thus indicating an operational regime typical of molecular diodes. Additionally, a negative differential resistance is observed due to the drop of the bias voltage along the structure, which yields to an energy mismatch of neighboring sites. Finally, the Fano factor reveals a stronger transport correlation for positive than for negative bias voltages in the disordered site configuration.