First-principles calculations of the dielectric properties of silicon nanostructures

We have investigated the static dielectric properties of silicon rods and slabs below 10 nm, in the long wavelength limit, by using first-principles density functional theory calculations. Surface structure is found to be the most important factor affecting the changes of the dielectric response at the nanoscale, compared to that of bulk Si, with significant differences observed between slabs and finite rods of similar lateral dimensions. (C) 2008 American Institute of Physics.