Influence of Quantum Interference on the Thermoelectric Properties of Molecular Junctions

Research output: Contribution to journalArticle

Abstract

Molecular junctions offer unique opportunities for controlling charge transport on the atomic scale and for studying energy conversion. For example, quantum interference effects in molecular junctions have been proposed as an avenue for highly efficient thermoelectric power conversion at room temperature. Toward this goal, we investigated the effect of quantum interference on the thermoelectric properties of molecular junctions. Specifically, we employed oligo(phenylene ethynylene) (OPE) derivatives with a para-connected central phenyl ring (para-OPE3) and meta-connected central ring (meta-OPE3), which both covalently bind to gold via sulfur anchoring atoms located at their ends. In agreement with predictions from ab initio modeling, our experiments on both single molecules and monolayers show that meta-OPE3 junctions, which are expected to exhibit destructive interference effects, yield a higher thermopower (with ∼20 μV/K) compared with para-OPE3 (with ∼10 μV/K). Our results show that quantum interference effects can indeed be employed to enhance the thermoelectric properties of molecular junctions.

Details

Authors
Organisations
External organisations
  • University of Michigan
  • Okinawa Institute of Science and Technology Graduate University
  • University of Konstanz
  • RWTH Aachen University
  • University of Copenhagen
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Theoretical Chemistry
  • Atom and Molecular Physics and Optics

Keywords

  • density functional theory, Molecular junctions, quantum interference, quantum transport, thermoelectricity, thermopower
Original languageEnglish
Pages (from-to)5666-5672
Number of pages7
JournalNano Letters
Volume18
Issue number9
Publication statusPublished - 2018 Sep 12
Publication categoryResearch
Peer-reviewedYes