1. Interface Dipoles Arising from Self-Assembled Monolayers on Gold: UV−Photoemission Studies of Alkanethiols and Partially Fluorinated Alkanethiols
- Author
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Ramon Colorado, Vicki H. Wysocki, Darrin L. Smith, Neal R. Armstrong, Paul A. Lee, Michael Hofmann, Nadine E. Gruhn, Dana M. Alloway, Amy L. Graham, and T. Randall Lee
- Subjects
chemistry.chemical_classification ,Chemistry ,Analytical chemistry ,Self-assembled monolayer ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,Crystallography ,X-ray photoelectron spectroscopy ,Monolayer ,Materials Chemistry ,Work function ,Physical and Theoretical Chemistry ,Thin film ,Methylene ,Spectroscopy ,Alkyl - Abstract
Gold surfaces modified with C3−C18-alkanethiols (CH3(CH2)X-1SH; HXSH; x = 3, 8, 12, 16, 18) and C16-alkanethiols, fluorinated at the outer 1, 2, 4, and 10 methylene positions (CF3(CF2)Y-1(CH2)XSH; FyHxSH; y = 1, x = 15; y = 2, x = 14; y = 4, x = 12; y = 10, x = 6) were characterized by He(I) UV-photoelectron spectroscopy (UPS). (Detailed X-ray photoelectron spectroscopic characterization of the partially fluorinated thin films is given in the Supporting Information). Long incubation times of the gold surface with the alkanethiol solutions lead to compact monolayer films for all of the alkanethiols, as indicated by the exponential decrease in emission intensity versus alkyl chain length for both the gold Fermi edge (UPS data), and by a parallel decrease in Au(4f) photoemission intensity using X-ray photoelectron spectroscopy. Changes in the effective work function of these surfaces due to the presence of significant interfacial dipoles are observed (i) as alkyl chain length is increased, and (ii) as the fr...
- Published
- 2003
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