Electrical field analysis in molecular electronics devices

The molecules conduction between two electrodes is generally described by Landauer formula ’I. The transmission through the molecules is determined by the alignment of molecular levels relative to the metal Fermi level’). The most important factor in determining the I-V characteristics of molecular conductor is probably the location of the Fermi energy of the metallic contact relative to the HOMO (Highest occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) levels ’). Unlike solids, molecules are capable of deforming in an external field. The introduction of an external field can enhance or reduce the interaction between the electronics states in metal-molecule-metal system. The electric field can modify the molecular levels with a shift in Fermi energy that could shrink the HOMOLUMO gap (HLG), making the difference between the Fermi energy and molecular levels smallest) that could have a significant implications for conductance.