Seebeck Coefficient of AuxGe1-x Thin Films Close to the Metal-Insulator Transition for Molecular Junctions

We experimentally study the thermoelectric properties of an AuxGe1-x thin-film alloy close to the metal-insulator transition (x = 19.5%). The thermoelectric characterization of the thin-film alloy shows a Seebeck coefficient comparable to that of Au thin film while preserving good thermal sensor properties, revealing the potential interest in its use in nanoscale thermoelectric systems. In particular, we demonstrate the ability to directly evaporate an AuxGe1-x thin film on different nanometric-thick molecular layers. A device engineering is proposed paving the way for investigation of the thermoelectricity of large-area nanometric-thick molecular layers, where the alloy is integrated as a contact electrode, fulfilling the double role of an in situ local heater and a high-resolution thermometer.