Evaluation of the Electronic Structure of Single‐Molecule Junctions Based on Current–Voltage and Thermopower Measurements: Application to C60 Single‐Molecule Junction

The electronic structure of molecular junctions has a significant impact on their transport properties. Despite the decisive role of the electronic structure, a complete characterization of the electronic structure remains a challenge. This is because there is no straightforward way of measuring electron spectroscopy for an individual molecule trapped in a nanoscale gap between two metal electrodes. Herein, a comprehensive approach to obtain a detailed description of the electronic structure in single‐molecule junctions based on the analysis of current–voltage (I–V) and thermoelectric characteristics is described. It is shown that the electronic structure of the prototypical C60 single‐molecule junction can be resolved by analyzing complementary results of the I–V and thermoelectric measurement. This combined approach confirmed that the C60 single‐molecule junction was highly conductive with molecular electronic conductances of 0.033 and 0.003 G0 and a molecular Seebeck coefficient of −12 μV K−1. In addition, we revealed that charge transport was mediated by a LUMO whose energy level was located 0.5≈0.6 eV above the Fermi level of the Au electrode. Right at the junction: Characterization of the electronic structure of the single‐molecule junctions is a key technology. In this paper, a comprehensive approach to obtain a full description of the electronic structure in single‐molecule junctions based on current–voltage and thermoelectric characteristics is described. This new technique reveals the electronic structure of the single C60 single‐molecule junction.