Angle-resolved photoelectron spectroscopy (ARPES) using synchrotron radiation was employed to study the electronic structure of a well-ordered single-domain Si(001)2×2-In surface. The existence of five surface state bands, denoted as (Formula presented), (Formula presented), (Formula presented), (Formula presented), and (Formula presented) is revealed within the bulk band gap between 0.6 and 2.2 eV in binding energy ((Formula presented)). The dispersions of these surface states are determined for most of the symmetry axes in the 2×2 surface Brillouin zone (SBZ), which turn out to be essentially identical to those observed for Si(001) 2×2-Al recently . Symmetries of the surface states with respect to two mirror axes of the SBZ are determined by the polarization dependence of ARPES intensities. A comparison to a theoretical calculation makes it possible to determine that the smallest (Formula presented) state (Formula presented) is due to the In dimer bond and (Formula presented), (Formula presented), (Formula presented), and (Formula presented) are due to bonds between In dimers and topmost Si atoms, and that the In dimers are parallel to the substrate Si dimers. Besides these five surface state bands, two other spectral features are observed within the bulk band gap, which can be related to similar features observed for a clean Si(001) surface.
|Number of pages||10|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 1996|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics