Self-assembled monolayers made of 6-(5-((6-((5-hexylthiophen-2-yl)ethynyl)- 9,10-bis(phenylethynyl)anthracen-2-yl)ethynyl)thiophen-2-yl)hexyl 3-(triethoxysilyl)propylcarbamate for ultrathin film transistors

Dong Uk Heo, Joo Bin Lee, Yoon Deok Han, Jinsoo Joo, Hosuk Lee, Hosun Lee, Dong Hoon Choi

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

A new functionalized triethoxysilane bearing an X-shaped, anthracene-based semiconducting molecule on one arm was designed and synthesized as a precursor for the preparation of a self-assembled monolayer (SAM) on a SiO2 substrate. 3-Isocyanatopropyl triethoxysilane was reacted with a monohydroxyl-terminated X-shaped, anthracene-based semiconducting molecule in the presence of tin catalyst. The 6-(5-((6-((5-hexylthiophen-2-yl)ethynyl)-9,10- bis(phenylethynyl)anthracen-2-yl)ethynyl)thiophen-2-yl)hexyl 3-(triethoxysilyl)propylcarbamate (BATHT-TEOS) was found to be stable and sufficiently reactive to form organic monolayers on hydroxylated SiO2 surfaces. The structures and properties of these SAMs were investigated using X-ray photoelectron spectroscopy, UV-vis absorption spectroscopy, photoluminescence (PL) spectroscopy, laser scanning confocal microscopy-PL spectrometry, and spectroscopic ellipsometry. In this work, BATHT-SAM was employed as an interfacial layer on SiO2 to fabricate ultrathin film transistors (UTFTs, active layer thickness ∼ 16.09 nm). The device UTFT-I, made of 0.06 wt % 5,5'-(9,10-bis(phenylethynyl)anthracene-2,6-diyl)bis(ethyne-2, 1-diyl)bis(2-hexylthiophene) (BATHT) solution on an n-octyltrichlorosilane-SAM/ SiO2 layer, showed no gate effect for the carrier transport behavior; however, the device UTFT-II, fabricated on BATHT-SAM/SiO2, exhibited field effect mobilities of 0.04 cm2 V-1 s-1 (Ion/off ∼ 6.3*- 103 to 1.0*- 10 4). This can be attributed to the effect of BATHT-SAM inducing uniform coverage and ordering of BATHT molecules as an upper layer.

Original languageEnglish
Pages (from-to)10948-10955
Number of pages8
JournalLangmuir
Volume28
Issue number29
DOIs
Publication statusPublished - 2012 Jul 24

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ASJC Scopus subject areas

  • Electrochemistry
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Materials Science(all)
  • Spectroscopy

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