The Drive Force of Electrical Breakdown of Large-Area Molecular Tunnel Junctions

Li Yuan, Li Jiang, Christian A. Nijhuis*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

5 Citations (Scopus)

Abstract

The origin of electrical breakdown of molecular tunnel junctions is systematically studied by determination of the breakdown voltages as a function of six types of bottom-electrodes (Au, Ag, Pt, Pd, Ni, and Cu) and different thickness of self-assembled monolayers of n-alkanethiolates, S(CH2)n–1CH3 with n = 2, 4, …, 18, with GaOx/EGaIn top contacts. It is found that at positive bias, the migration of metallic atoms is dominated by the wind force, but, at negative bias, both the wind force and direct force are involved in the mechanism of filament formation. Remarkably, the breakdown voltage is independent of the molecular length for short molecules (n < 10), and the breakdown field could be improved by a factor of ≈2 from 0.80 to 1.5 GV m−1 by replacing the Ag with Pt (or Ni) bottom electrodes. These findings give insights into the design of stable molecular junctions.
Original languageEnglish
Article number1801710
JournalAdvanced functional materials
Volume28
Issue number28
DOIs
Publication statusPublished - 11 Jul 2018
Externally publishedYes

Keywords

  • electrical breakdown
  • electromigration
  • molecular electronics
  • tunnel junction
  • wind force

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