Role of phonon in the thermal and electrical transports in metallic nanofilms

The electronic thermal transport in metallic nanofilms has been extensively studied. There are, however, rare reports on the influence of phonon on the thermal and electrical transports in metallic films. In the present work, equilibrium molecular dynamics with embedded-atom method is used to investigate the lattice thermal conductivity in a single-crystalline copper film. The results show that the lattice contribution to the total thermal conductivity is relatively small, nevertheless enhanced compared to that in bulk copper. The low-dimensional phonon system in metallic films is characterized by the elastic continuum model. In addition to the traditional boundary scattering, the reduced phonon group velocity and reduced Debye temperature are taken into account to discuss the finite size effect on phonon transport and electronic thermal resistivity and electrical resistivity.