Co on the H-passivated Si(001) surface: Density-functional calculations

We have presented an atomic and electronic structures, as well as chemical bonding of Co on the bare, partially H-passivated, and fully H-passivated Si(001)-(2×2) surface using density functional theory. There have been considered three different sites for Co on the surface; (1) an l-site (Co bonded to the lower lying Si-dimer component), (2) an h-site (Co bonded to the higher lying Si-dimer component), and (3) an i-site (intrarow position between adjacent Si dimer rows). The calculations indicate that for the i-site, the Co atom is located at nearly the same height as the Si dimers towards the vicinal region on the bare and partially H-passivated Si(001) surface. For all the remaining cases studied here, the Co atom prefers to stay at the subsurface site. •We present an atomic structure, electronic structure, and chemical bonding of Co on the bare, partially and fully H-passivated Si(001)-(2 × 2).•We try to understand the effect of H on Si surface considering Co passivation.•We present chemical potential.