Adsorption and decomposition of acetone on Si(0 0 1)

The adsorption of acetone on the Si(0 0 1) surface was investigated using the first-principles pseudopotential method within a generalized gradient approximation to the density functional theory. Our results indicate that [(CH3)2CO] adsorbs at low temperature in a [2 þ 2] cycloaddition reaction via C¼O radical to the dangling bonds of Si–Si dimers. The dissociation and desorption of the methyl and acetyl radicals was also investigated, pointing out that the most probable dissociation occurs with the formation of a CH2–CH2 structure over a Si–Si dimer and with the saturation of the other dimer by hydrogen atoms in a (2 2) reconstruction, and the desorption of a C¼O molecule. Calculated vibrational modes for the adsorbed systems are presented, with a view to contribute to further experimental investigations. # 2004 Elsevier B.V. All rights reserved.