Electronic structure of Sn/Si(111)-(3×3)R30°as a function of Sn coverage

We report an investigation of the electronic band structure of the Si x Sn( 1 - x )/Si( 111) - (3×3)R30° solid solution using angle-resolved photoemission. This reconstruction was studied in the coverage range between 0.15 and 0.40 monolayers at room and low temperature, with special emphasis on the analysis of the symmetry and morphology of the surface states and the metallic character as a function of temperature and coverage. While there is no indication of a (3 X 3) pattern at low temperature with structural techniques, strikingly clear features of this phase are found in the valence band analysis for a coverage of 0.33 ML. We present also an analysis of the influence of the Si intermixing in the surface-state behavior and metallic character.