Hot microcontact printing for patterning ITO surfaces. Methodology, morphology, microstructure, and OLED charge injection barrier imaging

Yoshihiro Koide, Matthew W. Such, Rajiv Basu, Guennadi Evmenenko, Ji Cui, Pulak Dutta, Mark C. Hersam, Tobin J. Marks

Research output: Contribution to journalArticle

61 Citations (Scopus)

Abstract

A soft lithographic microcontact printing (μCP) procedure is successfully applied for the first time to form densely packed organosilane self-assembled monolayers (SAMs) on the surface of ITO (Sn-doped In2O3) coated glass via a thermally activated deposition process. Hot microcontact printing (HμCP) enables localized transfer with 1.0-40 μm feature sizes of dense docosyltrichlorosilane (CH3(CH2)20CH2SiCl3 = DTS) monolayer patterns onto ITO, which reacts sluggishly under conventional μCP conditions. X-ray reflectivity measurements yield a thickness of 12.1 ± 0.1 Å and a surface roughness of 2.8 ± 0.1 Å for HμCP printed DTS films, which is well within the range for self-assembled monolayer formation, while the weak reflected intensity from conventionally prepared DTS films indicates a poorly organized monolayer structure. Noncontact mode AFM studies reveal that HμCP creates uniform SAMs over a wide area with excellent line edge resolution, while the original patterns are poorly transferred by conventional μCP, presumably due to the slow Si-O bond formation. Cyclic voltammetry of 1,1′-ferrocenedimethanol solutions using HμCP-derived, DTS SAM coated ITO working electrodes evidences good barrier properties, consistent with dense films. The DTS SAM patterns can be imaged by fabricating organic light-emitting diode (OLED) heterostructures on the patterned ITO. The DTS SAM role as a hole injection blocking layer enables patterned luminescence from the hot contact printed ITO surfaces.

Original languageEnglish
Pages (from-to)86-93
Number of pages8
JournalLangmuir
Volume19
Issue number1
DOIs
Publication statusPublished - Jan 7 2003

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ASJC Scopus subject areas

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

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