Use of angle-resolved photoemission and density functional theory for surface structural analysis of YSi2

[摘要] The atomic structure of two-dimensional yttrium silicide epitaxially grown on Si(111) was investigated by means of density functional theory calculations and angle-resolved photoemission experiments. The obtained accuracy of the calculations allowed to discriminate different surface arrangements in a quantitative way via comparing their theoretical band structure to the experimental result. Theoretically we find significant changes in the dispersion of a surface localized band upon varying the thickness of the topmost silicon bilayer. For a thickness of 0.4 Angstrom of the topmost silicon bilayer a strong asymmetry of the surface localized band with respect to Gamma is found, while a thickness of 0.8 Angstrom yields a more symmetric dispersion of the band. By comparison with the experimental photoemission results, which show a rather symmetric band around Gamma, we can conclude that the topmost bilayer has a thickness of 0.8 Angstrom. (C) 2004 Published by Elsevier B.V.

[发布日期] 2004-09-20

[效力级别]  Proceedings Paper

[关键词] density functional calculations;angle resolved photoemission;surface electronic phenomena (work function;surface potential, surface states, etc.);surface structure, morphology, roughness;and topography;metal semiconductor interfaces;yttrium