Si(110)16 × 2 and Si(110)2 × 3-Sb surfaces studied by photoemission and optical spectroscopy

The electronic properties of clean Si(110)16 × 2 and Si(110)2 × 3-Sb surfaces have been studied by angle resolved ultraviolet photoelectron spectroscopy (ARUPS) and surface differential reflectivity (SDR). For the clean 16 × 2 surface four surface states have been recognized by ARUPS and their dispersions have been mapped along the main symmetry lines in the surface Brillouin zone. SDR experiments revealed transitions between filled and empty surface states at ∼ 1.8, 2.4 and 2.9 eV. Antimony has been subsequently evaporated (about one monolayer) thus obtaining a 2 × 3 reconstruction. The surface electronic structure resulted to be strongly modified with three surface state bands observed in ARUPS along the [111] direction and no optical transitions detected by SDR in our energy range (1.3–3.5 eV).