Surface phonon-polariton mediated thermal conductivity enhancement of amorphous thin films

We predict theoretically that the effective in-plane thermal conductivity of polar, amorphous thin films can be increased by surface phonon-polaritons significantly beyond their intrinsic bulk values. We show that the thermal conductivity due to surface phonon-polaritons increases with decreasing film thickness. In particular, for a 40-nm-thick film of amorphous silicon dioxide, we calculate a total thermal conductivity of 40. 3em{0ex}W0. 2em{0ex}m^-10. 2em{0ex}K^-1 at 500 K, which is an increase of 100% over the intrinsic phonon thermal conductivity.