Interaction of ethylene with cleaved silicon surface

We have investigated the interaction of ethylene with cleaved silicon surface by LEED, AES, EELS and photoemission yield spectroscopy (PYS). The initial reconstruction 2×1 has remained visible at higher doses of ethylene (⩾1000 L). C2H4 has been adsorbed on Si(1 1 1)2×1 molecularly with an initial sticking coefficient S0=2×10-2 and at saturation the valence band has been fitted by a power law (E-Ei)2.5; Ei=(4.45±0.02)eV. The silicon surface has proved to be a scattering for photo-emitted electrons. This scattering is attributed to the dipole effect, introduced by adsorbed ethylene, and is distributed in a non-uniform way on the silicon surface.