Voltage-Induced Single-Molecule Junction Planarization

Research output: Contribution to journalLetterResearchpeer-review

  • Yaping Zang
  • E-dean Fung
  • Tianren Fu
  • Suman Ray
  • Marc H. Garner
  • Anders Borges
  • Michael L. Steigerwald
  • Satish Patil
  • Solomon, Gemma C.
  • Latha Venkataraman
Probing structural changes of a molecule induced by charge transfer is important for understanding the physicochemical properties of molecules and developing new electronic devices. Here, we interrogate the structural changes of a single diketopyrrolopyrrole (DPP) molecule induced by charge transport at a high bias using scanning tunneling microscope break junction (STM-BJ) techniques. Specifically, we demonstrate that application of a high bias increases the average nonresonant conductance of single Au–DPP–Au junctions. We infer from the increased conductance that resonant charge transport induces planarization of the molecular backbone. We further show that this conformational planarization is assisted by thermally activated junction reorganization. The planarization only occurs under specific electronic conditions, which we rationalize by ab initio calculations. These results emphasize the need for a comprehensive view of single-molecule junctions which includes both the electronic properties and structure of the molecules and the electrodes when designing electrically driven single-molecule motors.
Original languageEnglish
JournalNano Letters
Volume21
Issue number1
Pages (from-to)673-679
Number of pages7
ISSN1530-6984
DOIs
Publication statusPublished - 13 Jan 2021

ID: 261051121