Theoretical investigation of the structure and coverage of the Si(111)-OCH3 surface

Santiago D. Solares, David J. Michalak, William A. Goddard, Nathan S. Lewis

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23 Citations (Scopus)

Abstract

The surface structure, strain energy, and charge profile of the methoxylated Si(111) surface, Si(111)-OCH3, has been studied using quantum mechanics, and the results are compared to those obtained previously for Si(111)-CH3 and Si(111)-C2H5. The calculations indicate that 100% coverage is feasible for Si(111)-OCH3 (similar to the methylated surface), as compared to only ∼80% coverage for the ethylated surface. These differences can be understood in terms of nearest-neighbor steric and electrostatic interactions. Enthalpy and free energy calculations indicate that the formation of the Si(111)-OCH3 surface from Si(111)-H and methanol is favorable at 300 K. The calculations have also indicated the conditions under which stacking faults can emerge on Si(111)-OCH3, and such conditions are contrasted with the behavior of Si(111)-CH3 and Si(111)-CH2CH3 surfaces, for which stacking faults are calculated to be energetically feasible when etch pits with sufficiently long edges are present on the surface.

Original languageEnglish
Pages (from-to)8171-8175
Number of pages5
JournalJournal of Physical Chemistry B
Volume110
Issue number16
DOIs
Publication statusPublished - Apr 27 2006

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ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

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