Ab initio study of Si(001)2 × 1C chemisorption surface

Abstract The optimized structure of Si(001)2 × 1 C with monolayer coverage, is obtained by the first-principles molecular dynamics method with a plane-wave basis set. It is revealed that the symmetric dimer structure is stable, although the Si (001)2 × 1 surface prefers an asymmetric dimer structure, and that this surface shows a semiconducting feature with an indirect gap. Although the optimized dimer structure is rather flat, it is slightly raised from the substrate. The CC dimer bond is much shorter than the diamond single bond. These features are mainly due to the strong interaction between the carbon atoms.