Single-Molecule Junctions: Thermoelectricity at the Gate

Around half of the industrial energy consumption in the United States is lost through heat1. Collecting even a fraction of it to generate usable electricity could significantly reduce overall energy power consumption and, in turn, have a positive effect on the environment. One approach to transforming heat into electricity is through the thermoelectric effect — a phenomenon exhibited by certain materials in which a temperature difference induces a flow of carriers from a hot terminal to a cold terminal, creating an electrical voltage. The energy conversion efficiency of a thermoelectric material is proportional to the power factor, S2G, where S is the Seebeck coefficient and G the electrical conductance. However, developing materials that can offer both enhanced electrical conductances and Seebeck coefficients has proved to be a considerable challenge. Writing in Nature Nanotechnology, Pramod Reddy and co-workers at the University of Michigan2 now show that these two properties can be controlled and simultaneously enhanced in single-molecule junctions with the help of a gate electrode.