Influence of longitudinal electric field on the hot-phonon effect in quantum wells

Abstract

Articles you may be interested inElectron-confined longitudinal optical phonon interaction and strong magnetic field effects on the binding energy in GaAs quantum wells Analysis of the scattering of electrons by special vibrational modes in a GaAs quantum well with a thin AlAs middle barrier: Mobility modulated by a transversal electric field Hot carrier dynamics in a (GaInSb/InAs)/GaInAlAsSb superlattice multiple quantum well measured with mid-wave infrared, subpicosecond photoluminescence upconversion Using the Huang-Zhu model ͓K. Huang and B.-F. Zhu, Phys. Rev. B 38, 13377 ͑1988͔͒ for the optical phonons and associated carrier-phonon interactions in semiconductor superlattices, the effects of longitudinal electric field on the energy-loss rates ͑ELRs͒ of hot carriers as well as on the hot-phonon effect ͑HPE͒ in GaAs/ AlAs quantum wells ͑QWs͒ are studied systematically. Contributions of various bulklike and interface phonons to the hot-carrier relaxation are compared in detail, and comprehensively analyzed in relation to the intrasubband and intersubband scatterings for quantum cascade lasers. Due to the broken parity of the electron ͑hole͒ states in the electric field, the bulklike modes with antisymmetric potentials are allowed in the intrasubband relaxation processes, as well as the modes with symmetric potentials. As the interface phonon scattering is strong only in narrow wells, in which the electric field affects the electron ͑hole͒ states little, the ELRs of hot carriers through the interface phonon scattering are not sensitive to the electric field. The HPE on the hot-carrier relaxation process in the medium and wide wells is reduced by the electric field. The influence of the electric field on the hot-phonon effect in quantum cascade lasers is negligible. When the HPE is ignored, the ELRs of hot electrons in wide QWs are decreased noticeably by the electric field, but slightly increased by the field when considering the HPE. In contrast with the electrons, the ELRs of hot holes in wide wells are increased by the field, irrespective of the HPE.