Molecularly Controlled Stark Effect Induces Significant Rectification in Polycyclic-Aromatic-Hydrocarbon-Terminated n-Alkanethiolates

Soo Jin Cho, Gyu Don Kong, Sohyun Park, Jeongwoo Park, Seo Eun Byeon, Taekyeong Kim, Hyo Jae Yoon

Research output: Contribution to journalArticlepeer-review

33 Citations (Scopus)


The variation of the electronic structure of individual molecules as a function of the applied bias matters for the performance of molecular and organic electronic devices. Understanding the structure-electric-field relationship, however, remains a challenge because of the lack of in-operando spectroscopic technique and complexity arising from the ill-defined on-surface structure of molecules and organic-electrode interfaces within devices. We report that a reliable and reproducible molecular diode can be achieved by control of the conjugation length in polycyclic-aromatic-hydrocarbon (PAH)-terminated n-alkanethiolate (denoted as SC 11 PAH), incorporated into liquid-metal-based large-area tunnel junctions in the form of a self-assembled monolayer. By taking advantage of the structural simplicity and tunability of SC 11 PAH and the high-yielding feature of the junction technique, we demonstrate that the increase in the conjugation length of the PAH terminal group leads to a significant rectification ratio up to ∼1.7 × 10 2 at ±740 mV. Further study suggests that the Stark shift of the molecular energy resonance of the PAH breaks the symmetry of the energy topography across the junction and induces rectification in a temperature-independent charge-transport regime.

Original languageEnglish
Pages (from-to)545-553
Number of pages9
JournalNano Letters
Issue number1
Publication statusPublished - 2019 Jan 9

Bibliographical note

Funding Information:
This research was supported by NRF of Korea (NRF-2017M3A7B8064518 for H.J.Y.; NRF-2016R1D1A1B03931148 for T.K.). H.J.Y. also acknowledges support by the Future Research Grant of Korea University.

Publisher Copyright:
© 2018 American Chemical Society.


  • EGaIn
  • Stark effect
  • large area tunnel junction
  • molecular diode
  • polycyclic aromatic hydrocarbon
  • rectification
  • self-assembled monolayer

ASJC Scopus subject areas

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


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