Thermal reaction and desorption behaviors of 2,5-diiodothiophene on clean and passivated Au surfaces

Guangming Liu, Kunkul Ryoo, Seong Kim

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3 Scopus citations

Abstract

Thermal reactions and desorption behaviors of 2,5-diiodothiophene on Au were studied with temperature programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). Diiodo-substituted hetero-cyclic molecules are an important precursor molecule for photochemical production of conjugated polymers. This paper describes the surface reactions and multilayer structure of 2,5-diiodothiophene in the absence of photon irradiation. 2,5-Diiodothiophene adsorbs molecularly on Au at 100 K. At 200-300 K, the C-I bond of the molecule dissociates producing atomic iodine. The C-I bond cleavage appears to induce further dissociation of the thiophene ring structure. The iodine species desorb at 600-750 K from the surface. The dissociated carbon and sulfur remain on the Au surface even at 800 K. The desorption of thin multilayers occurs at ∼220 K. During the desorption of these layers, a clustering process seems to occur. The desorption of thick multilayer occurs at ∼235 K.

Original languageEnglish (US)
Pages (from-to)2967-2972
Number of pages6
JournalSurface Science
Volume601
Issue number14
DOIs
Publication statusPublished - Jul 15 2007

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All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

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