Charge storage model for hysteretic negative-differential resistance in metal-molecule-metal junctions

Abstract

Experimental results on the electrical characteristics of Hg-alkanethiol∕arenethiol-Au molecular junctions are used to develop a physical model for the hysteretic negative-differential resistance (NDR) for these, and possibly other, metal-molecule-metal junctions. The dependence of the room-temperature current-voltage characteristic on sweep direction and sweep rate is examined. Based on several specific electronic behaviors, it is concluded that the NDR is caused by slow charge capture (reduction or oxidation) during the forward sweep and the resultant effect on tunneling. The implications of this model on potential electronic applications are discussed.