Impact of impurities on the thermal conductivity of semiconductor nanostructures: first-principles theory.

The thermal conductivity kappa(T) of Si nanostructures containing impurities is calculated from first-principles using nonequilibrium molecular dynamics simulations in thermally "prepared" periodic supercells. For a given concentration of impurities, kappa exhibits strongly nonlinear variations with the mass of the impurity. There is a narrow range of conditions for which kappa is substantially reduced relative to that of the pure material. This suggests that the kappa of nanowire could be controlled with impurities and that nanoregions with a desired kappa could be implanted on chips.