Material Detail

Molecular electron transfer, as treated by the Marcus theory, strongly depends on nuclear motion as a way to achieve critical configurations in which charge rearrangement is possible. The electron tunneling process itself is assumed to occur in a static nuclear environment. In the application of the Landauer theory to conduction in molecular junctions, the electron transmission process is assumed to be elastic and nuclear motion is usually disregarded. This talk will focus several aspects of this issue. First, timescale criteria for disregarding or including nuclear motion in analyzing electron transmission through molecules and molecular layers will be presented. Second, the effect of nuclear motion on the overall transmission probability will be demonstrated for electron tunneling through water layers. Third, the effect of thermal relaxation and dephasing on the transition from tunneling to activated hopping as the dominant transmission mechanism will be considered. Finally, a framework for estimating heating and expected temperature rise in current carrying molecular junctions will be described. The latter issue requires consideration also of the heat conduction properties of molecular wires.

Disciplines:

• Science and Technology  / Nanotechnology