Surface state transition and surface band structure of silicone

Abstract

High-resolution energy loss spectroscopy has been studied with low-energy electrons scattered from clean silicon (111) surfaces. The spectra show losses due to transitions between occupied and empty "dangling bond" surface state bands. Two of such loss peaks centered around 0.54 and 2.25 eV are observed with surfaces exhibiting the metastable Si (111)-2xl cleavage structure, while after the structural conversion to the stable 7x7 structure only one loss centered around 1.7 eV is found. These peaks indicate two and one saddle points, respectively, in the energy difference function (E$_{1}(\underline{k}$) - E$_{2}$(k)) of the "dangling bond" surface bands correlated with the 2x1 and the 7x7 silicon (111) surface structures