Effects of stimulated optical phonon decay on hot carriers in GaAs

We have considered energy transfer from highly nonequilibrium electron gas to crystal lattice via emission of high-frequency longitudinal optical (LO) phonons and their subsequent transformations. At high intensity of electro n excitation, the daughter LA phonons resulting from LO-phonon decay accumu late in considerable numbers and cause the LO-phonon decay to be a stimulat ed process. The stimulated decay effectively decimates the LO phonons and t hus prevents their reabsorption by the electrons. These effects being incor porated in description of the electron-phonon kinetics, we have obtained co nsiderable intensification of energy transfer from the electron subsystem. We also qualitatively discuss the effects of stimulation for alternative ch annels of LO-phonon decay. (C) 1999 Elsevier Science B.V. All rights reserv ed.