Core-level photoemission study of 2D ordered Bi/Si(100) interfaces

A high resolution fore-level photoemission investigation of 2D ordered Bi l ayers grown on Si(100)-(2 x 1) is presented. We study the Si 2p and Bi 5d c ore-levels at room temperature as a function of coverage and in the reconst ructed phases. The different Bi structural configurations around the monola yer coverage and in the (2 x n)-reconstructed phase are derived from the co re-level lineshape evolution. By following the Fermi level pinning, the pre sence of Bi-induced occupied electronic states close to the Si mid-gap is s uggested. (C) 1999 Elsevier Science B.V. All rights reserved.