Enhancement of Thermoelectric Properties of Porphyrin-based Molecular Junctions by Fano Resonances

Abstract

Abstract Single-molecule porphyrin applications gain attention by using molecules as elementary blocks of electronic components involving metallic atoms. Theoretically, one type of molecular-scale porphyrin device is used in this article, consisting of organometallic single molecules with different metals (Zn, Mg, Cu and Fe), sandwiched between gold electrodes bound by thiol anchor groups. The transmission and Seebeck coefficients for Au|molecule|Au configurations were computed by using density functional theory (DFT). The findings show that there is a robust Fano resonance in the transport behaviour around the Fermi energy, only for the porphyrin-based device with Fe metal. This result is attributed to the destructive quantum interference between continuous and discrete states. This work not only indicates that there is a relationship between the electrical conductance and thermopower but also it introduces a promising strategy to affect and control these characteristics via creation of Fano phenomenon.