Characterization of indium-tin oxide interfaces using X-ray photoelectron spectroscopy and redox processes of a chemisorbed probe molecule: Effect of surface pretreatment conditions

Carrie Donley, Darren Dunphy, David Paine, Chet Carter, Ken Nebesny, Paul Lee, Dana Alloway, Neal R. Armstrong

Research output: Contribution to journalArticle

253 Scopus citations


Surface characterization of indium-tin oxide (ITO) thin films has been carried out with monochromatic X-ray photoelectron spectroscopy (XPS) following various solution pretreatments, RF air plasma etching or high-vacuum argon-ion sputtering. Commercially available ITO films show high concentrations of hydrolyzed oxides and oxy-hydroxides in the near-surface region, along with stoichiometric oxide (In2O3, SnO2) and variable levels of oxygen defect sites. XPS revealed that solution and vacuum treatments changed both the relative surface coverage of the hydroxides and, to a lesser extent, the concentration of oxide defect sites in the near-surface region. These pretreatments have a significant effect on both the coverage and electron-transfer rates for chemisorbed ferrocene dicarboxylic acid (Fc(COOH)2), with the air-plasma-etched ITO showing the highest surface coverage of Fc(COOH)2 and an RCA treatment showing the highest electron-transfer rates.

Original languageEnglish (US)
Pages (from-to)450-457
Number of pages8
Issue number2
StatePublished - Jan 22 2002


ASJC Scopus subject areas

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

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