A comparative study of the (111), (110) and (100) surfaces of silicon using the local density of states method applied to the bond orbital model

Abstract

The authors combine the local density of states method with the bond orbital model to study several surfaces of silicon. Relaxation, hydrogen chemisorption and a 2*1 reconstruction have been considered for the (111) surface. In addition, surface-state band structures and total densities of states are reported for both the ideal (100) surface and a model of its 2*1 reconstruction, using a slab model. By examining local densities of states which have been obtained in the same way for all the surfaces considered, it is possible to see the strong similarities in most of the valence band as well as the differences in the details of the dangling-bond surface states. The effect of the surface on the lower part of the valence band is seen to be insensitive to relaxation and reconstruction.