Resonant interaction of optical phonons with two-dimensional electron and hole space-charge layers on silicon

In inversion layers on silicon a resonant interaction of electrons and holes with optical phonons has been observed. In the vicinity of the q{}0 optical-phonon frequency of Si, intersubband spectra are superimposed by resonant structures which have Fano-type profiles and which differ significantly in strength and shape for electrons and holes and also for different surface orientations. A deformation-potential-type electron-phonon interaction can be deduced from our experiments which is confined to less than 3 nm at the Si-SiO₂ interface.