Electrode conformation-induced negative differential resistance and rectifying performance in a molecular device

Carrying out theoretical calculations using the nonequilibrium Green’s function method combined with the density functional theory, the transport properties of a carbon wire connected to two Au electrodes are investigated. The results show that the negative differential resistance and rectifying performance can be observed apparently when a pure carbon chain is connected to two asymmetric Au electrodes. The main origin of the negative differential resistance behavior is a suppression of the highest occupied molecular orbital resonance at certain bias voltage. Also shown is that it is possible to make the negative differential resistance disappear and rectifying performance be weakened only by adding side groups to a wire.