Simulation of electrical characteristics of a nanocontact “Au — Pentacene — Au”

Abstract

The paper presents the results of the computer simulation of the electrical characteristics (transmission spectrum, the density of states, the current-voltage characteristic (CVC), the differential conductivity) of the “Au — Pentacene — Au” nanocontact within the framework of the electron density functional theory in the local density approximation. Modeling of characteristic was implemented in the Atomistix ToolKit with Virtual NanoLab program. It is shown that, at a temperature of 100 K, on CVC exhibits weakly expressed N-shaped regions, which smooth out with increasing temperature. It was found that at a temperature of 300 K and a bias voltage of 2 V in a voltage range of 1.14÷1.4 V, a current drop from ∼ 14.5 μΑ to 10.5 μΑ is observed. A possible cause for the appearance of a negative differential resistance can be resonance tunneling of quasiparticles, which is confirmed by the appearance in the transmission spectrum of resonant peaks and due to the low dimensionality of the object under consideration. The results obtained can be useful in the calculation of new promising electronic devices of organic nanoelectronics.