Surface structure and energy bands of 1/3 ML Sn/Ge(111)

P. Gori; O. Pulci; A. Cricenti

doi:doi:10.1051/jp4:2006132018

10th International Conference on the Formation of Semiconductor Interfaces
C. Girardeaux, et al.
J. Phys. IV France 132 (2006) 91-94
DOI: 10.1051/jp4:2006132018

Surface structure and energy bands of 1/3 ML Sn/Ge(111)

P. Gori¹, O. Pulci² and A. Cricenti¹

¹ Istituto di Struttura della Materia, Consiglio Nazionale delle Ricerche, Rome, Italy
² INFM, Department of Physics, University of Rome Tor Vergata, Italy

Abstract
The geometrical and electronic structure of 1/3 monolayer of Sn on the Ge(111) surface is investigated within density functional theory. The well known $3\times 3$ and $\sqrt 3 \times \sqrt 3$ reconstructions are studied in details, performing also band structure calculations and simulating STM images. Our results confirm that the 1U-2D $3\times 3$ structure is the more favorable one, not only from an energetic point of view but also from a comparison with STM experiments. On the other hand, the static room temperature electronic band structure of the $\sqrt 3 \times \sqrt 3$ hardly compares with the available photoemission data, thus supporting the idea of a dynamical flipping of the Sn ad-atoms.