Abstract
The acoustic phonon radiation patterns and acoustic phonon spectra due to electron acoustic phonon interaction in double barrier quantum well have been investigated by solving both the kinetic equations for electrons and phonons. The acoustic phonon radiation patterns have strongly pronounced maximum in the directions close to the perpendicular to the quantum well direction. The radiation pattern anisotropy is explained in terms of possible electron transitions, nonequilibrium electron distribution function, and the Hamiltonian of electron-phonon interactions.