Optimizing the deposition rate of vacuum-grown n-octylphosphonic acid monolayer for low-voltage thin-film transistors

Swati Gupta, Helena Gleskova

Research output: Contribution to journalConference Contribution

1 Citation (Scopus)
107 Downloads (Pure)

Abstract

A self-assembled monolayer of n-octylphosphonic acid (C8PA) is prepared from vapor phase in vacuum. C8PA thickness corresponding to several monolayers is deposited on aluminum oxide (AlOx) and subsequently heated to leave a monolayer of chemisorbed molecules. The effect of C8PA deposition rate on a 15-nm-thick, bilayer AlOx/C8PA dielectric and low-voltage p-channel organic thin-film transistors (OTFTs) is studied. The increase in the deposition rate from 0.1 to 7.0 Å/s leads to increase in the field-effect mobility from 0.039 to 0.061 cm2/Vs, while the threshold voltage remains around −1.55 V. At the same time, the off-current is reduced from 2.3 × 10−12 to 1.3 × 10−12A, the subthreshold slope is lowered from 100 to 89 mV/decade and the on/off current ratio is increased from ∼105 to ∼106. The leakage current density of AlOx is reduced from 1 × 10−7 to 4 × 10−8 A/cm2 at 3 V when C8PA monolayer is added on top of it. In addition, pentacene grain size on AlOx/C8PA is larger than that on AlOx. The overall performance of AlOx/C8PA OTFTs is superior to that of AlOx OTFTs.
Original languageEnglish
Pages (from-to)135-138
Number of pages4
JournalSID Symposium Digest of Technical Papers
Volume44
Issue numberSupplement S1
DOIs
Publication statusPublished - Sep 2013
EventEuroDisplay 2013 - London, United Kingdom
Duration: 16 Sep 201319 Sep 2013

Keywords

  • low-voltage thin-film transistors
  • optimizing the deposition rate
  • vacuum-grown
  • n-octylphosphonic acid monolayer

Fingerprint Dive into the research topics of 'Optimizing the deposition rate of vacuum-grown n-octylphosphonic acid monolayer for low-voltage thin-film transistors'. Together they form a unique fingerprint.

Cite this