Current-Voltage Characteristics of Molecular Devices at Low Bias

We use density functional theory and the Green function formalism with charge energy effect included in the self-consistent calculation of the I-V characteristics of a single benzene ring with an appendage of cf₃, and identify some interesting properties of the I-V characteristics at low bias. The molecule picks up a fractional charge at zero bias, then the additional fractional charge produces a barrier on the junction of the molecule and contacts to perturb current flow on the molecule. This phenomenon may be useful for the design of future molecular devices.