STABILITY AND ELECTRONIC-PROPERTIES OF NANOSCALE SILICON CLUSTERS

The Si-28 and M@Si-28 (M=tetravalent atoms) clusters have been studied by the density-functional theory. We find that both Si-28 and C-28 clusters have similar electronic structures, and the dangling bonds of the Size cluster can be stabilized by some superatoms. The covalent interaction between the Si-5 superatom and Si-28 cluster opens a gap at the Fermi level, which makes the Si-5@Si-28 cluster kinetically stable. In good agreement with experiments, a strong similarity in the density of states between silicon clusters and bulk phase has been observed.