Thermopower in Underpotential Deposition-Based Molecular Junctions.
Peng HeAbdalghani H S DaaoubSara SangtarashHatef SadeghiHyo Jae YoonPublished in: Nano letters (2024)
Underpotential deposition (UPD) is an intriguing means for tailoring the interfacial electronic structure of an adsorbate at a substrate. Here we investigate the impact of UPD on thermoelectricity occurring in molecular tunnel junctions based on alkyl self-assembled monolayers (SAMs). We observed noticeable enhancements in the Seebeck coefficient of alkanoic acid and alkanethiol monolayers, by up to 2- and 4-fold, respectively, upon replacement of a conventional Au electrode with an analogous bimetallic electrode, Cu UPD on Au. Quantum transport calculations indicated that the increased Seebeck coefficients are due to the UPD-induced changes in the shape or position of transmission resonances corresponding to gateway orbitals, which depend on the choice of the anchor group. Our work unveils UPD as a potent means for altering the shape of the tunneling energy barrier at the molecule-electrode contact of alkyl SAM-based junctions and hence enhancing thermoelectric performance.
Keyphrases
- single molecule
- ionic liquid
- density functional theory
- molecular dynamics
- sensitive detection
- molecular dynamics simulations
- reduced graphene oxide
- solid state
- magnetic resonance imaging
- magnetic resonance
- metal organic framework
- diffusion weighted imaging
- quantum dots
- decision making
- anti inflammatory
- perovskite solar cells