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

The thermal conductivity κ(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, κ exhibits strongly nonlinear variations with the mass of the impurity. There is a narrow range of conditions for which κ is substantially reduced relative to that of the pure material. This suggests that the κ of nanowire could be controlled with impurities and that nanoregions with a desired κ could be implanted on chips.