PROBING OF ELECTRON PHONON-SCATTERING IN IONIC SOLIDS BY XUV-INDUCED ELECTRON-EMISSION SPECTROSCOPY

The absorption spectra, the pulse and current quantum yield spectra of electron emission and the energy distributions of emitted electrons for the XUV-induced electron emission of NaCl and KBr have been measured. The values of the mean electron escape depth, 43 nm for NaCl and 34 nm for KBr, have been established. In order to understand the role of various elementary processes, particularly of the electron-phonon scattering, an attempt is made to reproduce the main regularities of the experimental spectra by a Monte Carlo simulation of the XUV-induced electron emission. The model describes reasonably well several features of the electron emission (dependence on the photon absorption depth, energy distribution, mean escape depth). It appears that for high-energy (> 2-3 eV) conduction electrons the electron-phonon scattering is mainly due to acoustic phonons.