Transition between Nonresonant and Resonant Charge Transport in Molecular Junctions

Songsong Li, Hao Yu, Jialing Li, Nicholas Angello, Edward R. Jira, Bo Li, Martin D. Burke, Jeffrey S. Moore, Charles M. Schroeder

Research output: Contribution to journalArticlepeer-review

Abstract

Efficient long-range charge transport is required for high-performance molecular electronic devices. Resonant transport is thought to occur in single molecule junctions when molecular frontier orbital energy levels align with electrode Fermi levels, thereby enabling efficient transport without molecular or environmental relaxation. Despite recent progress, we lack a systematic understanding of the transition between nonresonant and resonant transport for molecular junctions with different chemical compositions. In this work, we show that molecular junctions undergo a reversible transition from nonresonant tunneling to resonant transport as a function of applied bias. Transient bias-switching experiments show that the nonresonant to resonant transition is reversible with the applied bias. We determine a general quantitative relationship that describes the transition voltage as a function of the molecular frontier orbital energies and electrode Fermi levels. Overall, this work highlights the importance of frontier orbital energy alignment in achieving efficient charge transport in molecular devices.

Original languageEnglish (US)
Pages (from-to)8340-8347
Number of pages8
JournalNano letters
Volume21
Issue number19
DOIs
StatePublished - Oct 13 2021

Keywords

  • molecular electronics
  • resonant transport
  • scanning tunneling microscope break-junction (STM-BJ)

ASJC Scopus subject areas

  • General Chemistry
  • Condensed Matter Physics
  • Mechanical Engineering
  • Bioengineering
  • General Materials Science

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