Photoemission Measurements of Step-Dependent Surface States on Cleaved Silicon (111)

Abstract

Ultraviolet photoemission spectroscopy has been used to measure surface states on cleaved silicon with varying step-atom densities determined by low-energy-electron diffraction. For high step densities (\ensuremath{\sim} 10%) a new surface-state peak is found at an energy 0.4 eV higher than the main surface-state peak. These measurements are the first demonstration that surface-state photoemission spectra depend strongly on cleavage steps.