Adsorption of ethylene on Sn and In terminated Si(001) surface studied by photoelectron spectroscopy and scanning tunneling microscopy
Abstrakt
Interaction of ethylene (C2H4) with Si(001)-Sn-2 x 2 and Si(001)-In-2 x 2 at room temperature has been studied using core level (C 1s) X-ray photoelectron spectroscopy with synchrotron radiation and scanning tunneling microscopy. Sn and In form similar dimer chains on Si(001) 2 x 1, but exhibit different interaction with ethylene.
While ethylene adsorbs on top of Sn dimers of the Si(001)-Sn-2 x 2 surface, the Si(001)-In-2 x 2 surface turned out to be inert. Furthermore, the reactivity of the Sn terminated surface is found to be considerably decreased in comparison with Si(001) 2 x 1.
According to the proposed adsorption model ethylene bonds to Sn dimers via [2 + 2] cycloaddition by interacting with their pi dimer bonds. In contrast, indium dimers do not contain p bonds, which renders the In terminated Si(001) surface inert for ethylene adsorption.
Published by AIP Publishing.