Temperature dependence of thermopower in molecular junctions

Abstract

The thermoelectric properties of molecular junctions are of considerable interest due to their promise for efficient energy conversion. While the dependence of thermoelectric properties of junctions on molecular structure has been recently studied, their temperature dependence remains unexplored. Using a custom built variable temperature scanning tunneling microscope, we measured the thermopower and electrical conductance of individual benzenedithiol junctions over a range of temperatures (100 K–300 K). We find that while the electrical conductance is independent of temperature, the thermopower increases linearly with temperature, confirming the predictions of the Landauer theory.