Orientation effect on the electronic transport properties of C6 cluster

The effects of orientation on the electronic transport properties of C6 monocyclic ring bound to two Al(1 0 0) electrodes are investigated by density functional theory (DFT) combining with non-equilibrium Green’s-function (NEGF) method. It is found that the equilibrium conductance of the system shows an oscillatory behavior with the angle increasing between the ring plane and the transport direction. The changes of coupling strength and charge transfer between the cluster and the electrodes make a massive contribution to the oscillatory behavior. The calculated I–V characteristics for the cluster show different behaviors with different rotation angles. In certain case, the current increases monotonously and nonlinearly. In the other cases, small negative differential resistance (NDR) is observed.