GAMMA TO X-Z ELECTRON-TRANSFER TIMES IN TYPE-II GAAS ALAS SUPERLATTICES DUE TO EMISSION OF CONFINED AND INTERFACE PHONONS/

We calculate the Gamma --> X-z electron transfer times due to the emis sion of confined and interface LO phonons in type-II GaAs-AlAs and AlG aAs-AlAs superlattices. A dielectric continuum model is employed to de scribe the electron-phonon interaction, and the electron envelope wave functions are obtained from a Kronig-Penney model. The calculated tran sfer times are in good agreement with available experimental results. We have used two different sets of AlAs X-valley effective masses obta ined from different experiments and we show that the transfer times ca lculated with the heavier masses are in closer agreement with the meas ured data. (C) 1998 Academic Press Limited.