ELECTRONIC-STRUCTURE OF THE SI(111)SQUARE-ROOT-3XSQUARE-ROOT-3 SURFACE WITH COLUMN-V ADATOMS

Energy band calculations have been performed in the LDA and Pseudopotential formalism for the milk-stool adsorption model recently presented for column V adatoms with √ × √3 superlattice structure on the Si(111) surface. The obtained electronic structure for As adatoms can be well understood in the bond picture with sp3 orbitals of the adatoms, and is in qualitative agreement with spectroscopic data. Total energy analysis for this model leads to milk-stool parameter values nearly equal to those associated with the atomic radii of the adsorbate and substrate atoms. The adsorption energy per adatom has been calculated, and this model is found to be more stable than the H3 adsorption model by 2.0 eV. © 1990.