Inelastic electron-boundary scattering in thin films

Inelastic electron scattering at the interface is one of the basic processe s of the electron-phonon interaction in thin films, nanostructures, and low -dimensional conductors. This scattering process determines the temperature -dependent resistivity and electron dephasing in a wide temperature range. It also provides a new channel for energy transfer from the film electrons to the substrate phonons. Inelastic electron-boundary scattering allows us to explain the observed decrease of the Kapitza conductivity at the transit ion to the superconducting state and a value of the Kapitza conductance for pairs of materials with rather different acoustic impedances. It results i n a nonequilibrium component of the photoresponse with a picosecond decay t ime proportional to the film thickness that has been recently observed in Y BaCuO ultrathin films. (C) 1999 Elsevier Science B.V. All rights reserved.