Silicon monoxide clusters: The favorable precursors for forming silicon nanostructures

The energetically most favorable configurations of Si monoxide clusters (SiO)_n for n ranging from 3 to 21 were studied, and their corresponding electronic properties were calculated using density functional theory (DFT). To understand the formation of Si cores, the binding energies of some (SiO)_n clusters with the configurations in which an O atom resides in the Si cores, were calculated. The DFT calculations show that the energetically most favorable structures of silicon monoxide clusters for n≥5 contain sp³ Si core surrounded by a silicon oxide sheath. The frontier orbitals of the clusters are localized to a significant degree on the silicon atoms on the surface.