Structure effects on inter- And intra-band scattering of electrons in GaAs/Al_xGa_1-xAs and strained In_xGa _1-xAs/GaAs quantum wells

Based on the dielectric continuum model, we have studied the dependence of electron-optical phonon scattering rates in GaAs/Al_xa _1-xAs quantum wells with different structure parameters. It was found that the dependence of scattering rates of symmetric interface mode on Al composition in the barrier was stronger than that of the confined mode. The average phonon energy emitted by hot electrons in GaAs/Al_xGa _1-xAs quantum wells with various Al composition was estimated and the calculated value agrees with the experimental results qualitatively. For the dependence on the well width, scattering rates of the S+ mode dropped considerably as the well width is increased. The hot electron-neutral acceptor luminescence spectrum of the strained In_xGa_1-xAs/GaAs quantum well sample shows an oscillation period of about 22 meV which indicates that the hot electrons relaxed mostly through emissions of the InAs confined phonons.