Covalent Superlattice Structures at Silicon (111) Surfaces

Abstract
Low-energy electron-diffraction and photoemission data are presented for Si(111) surfaces with 2 × 1 and 7 × 7 superlattices, as well as for the disordered surface obtained in the transition from one to the other. Together with work-function measurements these data suggest two different models for the two superlattices.