Electronic transport across planar gold clusters of eight and nine atoms

Abstract

The transport properties of gold clusters with eight and nine atoms between gold electrodes are investigated by using non-equilibrium Green’s function method combined with density functional theory. Negative differential resistance effect is found both in Au8 and Au9. From a new respect, the mechanism for the negative differential resistance effect is explored through calculating the number of electrons of the atoms in the clusters at different bias voltages. When Au9 takes vertical orientation, it is found that the voltage can change the coupling strength of the sandwiched system. When the value of the voltage is small, the current increases with decreasing of the cluster-electrode separation. But when the voltage increases to a certain value, the current decreases with decreasing of the cluster-electrode separation. When Au9 takes parallel orientation, different from other electronic transport systems, it is found that the transport behaviors for Au9 are not sensitive to the cluster-electrode separation, showing that this configuration has a better transport stability over the changes in distance, which may provide some new clues for developing future electron device.