Building Ge Nanowires on As-Partially-Adsorbed Si(001) 2 × 1 Surface: An Ab Initio Study

Through ab initio simulations, we demonstrate a new scheme for self-assembling semiconductor nanostructures on the Si substrate by controlling the surface stress or strain. The scheme entails a two-step process: (a) an adjusting step for the lattice constants of Si surface using the partial adsorption of surface-active species on Si, followed by (b) self-assembly process of difficultly-attached atoms on the exposed Si surface. Using this scheme, we construct Ge-dimer nanowires, exhibiting typical semiconductor characteristic, on the As-partially-adsorbed Si(001) surface. This is beneficial to realize nanoscale Si-based devices for miniaturization.