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HL: Halbleiterphysik

HL 36: Quantenpunkte und -dr
ähte: Optische Eigenschaften I

HL 36.6: Vortrag

Donnerstag, 11. März 2004, 11:30–11:45, H17

Many-body theory of carrier capture and relaxation in semiconductor quantum-dot lasers — •Torben Roland Nielsen, Paul Gartner, and Frank Jahnke — Institute for Theoretical Physics, University of Bremen, 28334 Bremen, Germany

In quantum-dot laser devices containing a quasi two-dimensional wetting layer, a pump process initially populates the letting-layer states. The scattering of carriers from these spatially-extended quasi two-dimensional states into the quantum-dot states as well as the relaxation of carriers between the quantum-dot levels are studied theoretically.
Based on the wave functions for the coupled quantum-dot/wetting-layer system interaction matrix elements are calculated for carrier-carrier Coulomb interaction and carrier-phonon interaction. Scattering rates for various capture and relaxation processes are evaluated under quasi-equilibrium conditions.
For elevated carrier densities in the wetting layer, Coulomb scattering provides processes with capture (relaxation) times typically faster than 10ps (1ps). When energy conservation allows for interaction with LO-phonons, comparable rates are obtained.