Electron capture in GaAs quantum wells via electron-electron and optic phonon scattering

Electron capture times in a separate confinement quantum well (QW) structure with finite electron density are calculated for electron-electron (e-e) and electron-polar optic phonon (e-pop) scattering. We find that the capture time oscillates as function of the QW width for both processes with the same period, but with very different amplitudes. For an electron density of 10^11 cm^-2 the e-e capture time is 10-1000 times larger than the e-pop capture time except for QW widths near the resonance minima, where it is only 2-3 times larger. With increasing electron density the e-e capture time decreases and near the resonance becomes smaller than the e-pop capture time. Our e-e capture time values are two-to-three orders of magnitude larger than previous results of Blom et al. [Appl. Phys. Lett. 62, 1490 (1993)]. The role of the e-e capture in QW lasers is therefore readdressed.Comment: 5 pages, standard LaTeX file + 5 PostScript figures (tarred, compressed and uuencoded) or by request from [email protected], accepted to Appl. Phys. Let

Self-Consistent Analysis of Carrier-Transport and Carrier-Capture Dynamics in Quantum Cascade Intersubband Semiconductor Lasers

Abstract-A methodology for the self-consistent analysis of carrier transport and carrier capture aspects of the dynamics of quantum cascade intersubband semiconductor lasers is described in this paper. The approach is used to analyze two prototype quantum cascade lasers. The self-consistent analysis incorporates the calculation of the electron densities and temperatures in each subband, together with the intersubband relaxation time. In the calculation of the relaxation time, we take into account the electron interaction with polar optical and acoustic phonons, as well as electron degeneracy. In addition, we also calculate the capture time, considering backward processes that play a role in the electron transition from an injection into an active region. The calculations indicate intersubband relaxation times of order 1 ps and capture times of order 100 fs

Phonon Confinement and Electron Capture Time in Quantum Well

The electron capture time via an electron-polar optical phonon interaction is calculated considering the confinement of a phonon in a GaAs quantum well laser structure. The effect of the phonon confinement decreases the electron capture time about twice comparing the electron capture time obtained from the interaction of an electron with the bulk phonon