Peculiarity of electron–phonon energy exchange in metal nanoparticles and thin films

The size dependence of electron-lattice energy exchange in nanoparticles has been studied. Both surface and bulk energy exchange parameters are examined and it is demonstrated that the bulk energy exchange has non-monotonic oscillations versus size of the particles. It has been found that the amplitude of such oscillations increases with decreasing a particle size until the critical size reaches Lc. These bulk interaction related oscillations disappear for the particles less than Lc, and only the surface energy exchange remains as the energy flow between electrons and phonons subsystems. It has been shown that there exists an interval of particles sizes with total energy exchange of few orders less than in massive bulk metals. This condition is crucial for existence of hot electrons in stationary conditions in metal nanoparticles, metal island films and thin films as have been observed experimentally.