Interpretation of the photoemission spectra of Pb/Si(111)-(7×7) in the initial stages of the Pb chemisorption:: a theoretical study

• Published in: Surface science 1998-10, Vol.416 (1), p.274-287
• Main Authors: Sonnet, Ph, Stauffer, L, Ezzehar, H, Minot, C
• Format: Article
• Language: English
• Subjects: Adatoms; Chemisorption; Chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; General and physical chemistry; General, apparatus; Impurity and defect levels; energy states of adsorbed species; Lead; Physics; Semi-empirical models and model calculations; Silicon; Surface and interface electron states; Surface physical chemistry; Surface structure
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/S0039-6028(98)00612-8

In a recent theoretical study of the adsorption and diffusion mechanisms of Pb on the Si(111)-(7×7) surface in the initial stages of the Pb chemisorption, two adsorption mechanisms were especially considered: (i) adsorption of Pb atoms on Si dangling bonds; (ii) Pb adsorption with formation of Pb clusters. The second mechanism was found to be more favorable than the first one, but the two mechanisms may coexist. The tendency to agglomeration was explained by strong interaction between the Pb atoms. In this paper, we focus on an interpretation of the photoemission spectra observed for the Pb/Si(111)-(7×7) system. Densities of states performed on models based on these two mechanisms allow us to propose an interpretation for the two surface states experimentally observed in the projected band structure of Pb/Si(111)-(7×7).