Electronic-structure theory of the dimers adatoms and stacking fault model on Si(111) reconstructed surface—comparison with scanning tunneling spectroscopy

Abstract

The electronic structure of the Si(111) 5×5 dimers adatoms and stacking (DAS) model has been calculated in the slab geometry, using the local density approximation (LDA) and norm-conserving pseudopotential method. Surface states due to three kinds of dangling bonds are obtained, i.e., of the adatoms, the first layer atoms, and in the corner holes. The local densities of states have been calculated on these dangling bond sites. Since those of 5×5 are expected to be different from those of 7×7, a qualitative comparison of these results with the measured scanning tunneling spectroscopy (STS) of 7×7 has been made. In general, qualitative features agree well with the observed ones.