Si(100)1×1-Sb and Si(100)2×1-Sb surfaces studied with angle-resolved photoemission and surface differential reflectivity

Angle-resolved photoelectron spectroscopy and surface differential reflectivity have been used to study the electronic structure of Si(100):Sb-1×{}1 and Si(100):Sb-2×{}1 surfaces. For both surfaces, one occupied surface-state band has been mapped along the [010] and [011] directions. Both surfaces show a semiconducting behavior with a gap of 1.6 eV for the 1×{}1-Sb and 1.4 eV for the 2×{}1-Sb surface. A minimum-energy position at the Fermi level is derived for the empty surface-state band. The results are also compared with those obtained for the clean Si(100)2×{}1 surface.