5 research outputs found
Electronic Structure of Te and As Covered Si(211)
Electronic and atomic structures of the clean, and As and Te covered Si(211)
surface are studied using pseudopotential density functional method. The clean
surface is found to have (2 X 1) and rebonded (1 X 1) reconstructions as stable
surface structures, but no \pi-bonded chain reconstruction. Binding energies of
As and Te adatoms at a number of symmetry sites on the ideal and (2 X 1)
reconstructed surfaces have been calculated because of their importance in the
epitaxial growth of CdTe and other materials on the Si(211) surface. The
special symmetry sites on these surfaces having the highest binding energies
for isolated As and Te adatoms are identified. But more significantly, several
sites are found to be nearly degenerate in binding energy values. This has
important consequences for epitaxial growth processes. Optimal structures
calculated for 0.5 ML of As and Te coverage reveal that the As adatoms dimerize
on the surface while the Te adatoms do not. However, both As and Te covered
surfaces are found to be metallic in nature.Comment: 17 pages, 9 figures, accepted for publication in Phys. Rev.