Transport and noise in organic field-effect devices

The transport and fluctuation properties of organic molecules ordered parallel between two Au contact leads are investigated by the method of surface Green's function. From first-principles simulation the relevant hopping parameters are extracted and used to calculate nonlinear transport coefficients with respect to an external bias voltage. A staggering of conductance is found in dependence on the number of molecules squeezed in between the contacts. The thermal properties show an anomalous behavior whenever the voltage reaches the values of the molecular energy levels active for transport. The thermoelectric figure of merit shows a resonance allowing one to reach values even larger than one.