AVS 51st International Symposium
    Surface Science Monday Sessions
       Session SS2-MoM

Paper SS2-MoM7
Carbonyl Chemistry at the (100)-2x1 Semiconductor Interface

Monday, November 15, 2004, 10:20 am, Room 210C

Session: Functionalization of Semiconductor Surfaces
Presenter: M.A. Filler, Stanford University
Authors: M.A. Filler, Stanford University
S.F. Bent, Stanford University
Correspondent: Click to Email
Several recent studies of the covalent attachment of organic molecules at group-IV (100)-2x1 semiconductor interfaces reveal that even for simple compounds, complex bonding geometries that may involve multiple surface dimers are probable. In an attempt to gain further insight into the fundamental thermodynamics and kinetics of intra- and interdimer bonding pathways, we have studied the reactions of acetone and acetaldehyde on Si(100)-2x1 and Ge(100)-2x1 using a combination of infrared and X-ray photoelectron spectroscopy. For the Ge(100)-2x1 surface, infrared data of both acetone and acetaldehyde reveal a low coverage peak near 1510 cm@super -1@. Isotopically-labeled derivatives of these compounds provide evidence that this mode corresponds to an interdimer adsorption product where a carbonyl moiety donates charge to a neighboring dimer atom. Additional absorption peaks are observed near 1675 cm@super -1@ for moderate surface coverages and at 1600 cm@super -1@ near saturation, likely resulting from @nu@(C=O) and @nu@(C=C) stretching modes, respectively. These data suggest that, in addition to the previously reported ene product, carbonyl-containing compounds can react to form a C-H dissociation product where the carbonyl moiety remains intact. Results will be discussed within the context of classical organic chemistry, mainly keto-enol tautomerization, acidity, and hydrate formation.