Complete mapping of the thermoelectric properties of a single molecule

Pascal Gehring, Jakub K. Sowa, Chunwei Hsu, Joeri de Bruijckere, Martijn van der Star, Jennifer J. Le Roy, Lapo Bogani, Erik M. Gauger, Herre van der Zant

Research output: Contribution to journalLetterpeer-review

4 Citations (Scopus)
1 Downloads (Pure)

Abstract

Theoretical studies suggest that mastering the thermocurrent through single molecules can lead to thermoelectric energy harvesters with unprecedentedly high efficiencies.1,2,3,4,5,6 This can be achieved by engineering molecule length,7 optimizing the tunnel coupling strength of molecules via chemical anchor groups8 or by creating localized states in the backbone with resulting quantum interference features.4 Empirical verification of these predictions, however, faces considerable experimental challenges and is still awaited. Here we use a novel measurement protocol that simultaneously probes the conductance and thermocurrent flow as a function of bias voltage and gate voltage. We find that the resulting thermocurrent is strongly asymmetric with respect to the gate voltage, with evidence of molecular excited states in the thermocurrent Coulomb diamond maps. These features can be reproduced by a rate-equation model only if it accounts for both the vibrational coupling and the electronic degeneracies, thus giving direct insight into the interplay of electronic and vibrational degrees of freedom, and the role of spin entropy in single molecules. Overall these results show that thermocurrent measurements can be used as a spectroscopic tool to access molecule-specific quantum transport phenomena.
Original languageEnglish
Pages (from-to)426-430
Number of pages5
JournalNature Nanotechnology
Volume16
Issue number4
Early online date1 Mar 2021
DOIs
Publication statusPublished - Apr 2021

ASJC Scopus subject areas

  • Bioengineering
  • Atomic and Molecular Physics, and Optics
  • Biomedical Engineering
  • Materials Science(all)
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Fingerprint

Dive into the research topics of 'Complete mapping of the thermoelectric properties of a single molecule'. Together they form a unique fingerprint.

Cite this