Based on the first-principles computational method and elastic scattering Green＇s function theory, we have investigated the effect of gate electric field on electronic transport properties of a series of single organic molecular junctions theoretically. The numerical results show that the molecular junctions that have redox centers and relatively large dipole moments parallel gate direction can respond to the gate electric field remarkably. The current-voltage properties of 2,5-dimethyl-thiophene-dithiol present N-channel-metal-oxide-semiconductorlike characteristics. Its distinct current-voltage properties can be understood from the evo- lution of eigenvalues, coupling energies, and atomic charges with gate electric field.
