Tunneling spectroscopy of theSi(111)2×1surface

Abstract

Scanning tunneling spectroscopy has been used to observe electronic band features of the $\mathrm{Si}(111)2\ifmmode\times\else\texttimes\fi{}1$ surface, focusing on the size of the surface-state band gap. It is shown that peak positions in the normalized conductance, $(dI/dV)/(I/V),$ which are used to characterize the tunneling spectrum, are shifted slightly towards zero volts compared to the corresponding band structure features. A corrected band gap of $0.59\ifmmode\pm\else\textpm\fi{}0.04$ eV is obtained for this surface.