title: Microscopic origin of the reduced thermal conductivity of silicon nanowires.
abstract: We designed nanowires with a tailored surface structure and composition and with specific core defects to investigate the microscopic origin of the reduced thermal conductivity of Si at the nanoscale. We considered a diameter (15 nm) comparable to that of systems fabricated in recent experiments and we computed the thermal conductivity using equilibrium molecular dynamics simulations. We found that the presence of a native oxide surface layer may account for a tenfold to ~30-fold decrease in conductivity, with respect to bulk Si, depending on the level of roughness. However it is only the combination of core defects and surface ripples that enables a decrease close to 2 orders of magnitude, similar to that reported experimentally.
authors.affiliation: Department of Chemistry, University of California, Davis, California 95616, USA.
authors.forename: Yuping
authors.initials: Y
authors.lastname: He
authors.forename: Giulia
authors.initials: G
authors.lastname: Galli