Intersubband transition rates of localized electron-phonon interaction in structural defect superlattices

We investigate the intersubband-transition rates of in-gaps electrons assisted by localized-interface-optical-phonons (LIOPs) in AlAs/GaAs SL with a defect layer for different widths and different materials of defect layer and constituent layers. The rates are calculated under Fermi's golden rule and by using transfer-matrix method and on the basis of the dielectric continuum theory. The dependence of the maximum transition rate on the energy spacing between the initial and final states of in-gaps electrons, involving different LIOP modes is revealed. The results show that the intersubband-transition rates between the in-gaps states of electrons significantly depend not only on the structural configurations of the defect layer but also on physical and geometrical parameters of the systems as well as nature of the LIOP modes involved in the transition processes.