EFFECTS OF INTERFACE-PHONON SCATTERING IN 3-INTERFACE HETEROSTRUCTURES

A detailed study of the electron-optical-phonon interaction in an asym metric one-well/one-barrier heterostructure is given. Dispersion relat ions and phonon potential distributions for interface phonon modes are derived in the framework of the macroscopic dielectric continuum mode l. It is found that for intrawell relaxation processes the sum of the scattering rates by all interface polar-optical phonon modes is approx imately independent of the width of the barrier layer. Consequently, a simplified Hamiltonian for electron-phonon interaction in a single qu antum well can be used for scattering rate calculation in multiple het erointerface structures. The combined scattering rates by interface an d confined phonon modes are compared with the results obtained in an i dealized model using the bulklike phonon spectrum. The practical inval idity of the latter approximation is shown for electron kinetic energi es comparable with the typical energy of optical phonons in the hetero structure. (C) 1998 American Institute of Physics.