Analysis of the Atomic Structure of the Si(111)?3??3-Bi Surface by X-Ray Photoelectron Diffraction

It is found by X-ray photoelectron spectroscopy and LEED that the saturation coverage of Bi is one monolayer for the Si(111)√3×√3-Bi surface. Azimuthal dependence of Bi 4d photoelectron diffraction has been measured for the Si(111)√3×√3-Bi surface and analyzed kinematically. The results of the analysis have confirmed the presence of Bi-triplets with sides of 3.1 A as proposed by X-ray diffraction. It is further found that the Bi-triplets form an overlayer on the substrate.