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DS: Fachverband Dünne Schichten
DS 7: Nanophotonics - Theory of Nanophotonic Devices III
DS 7.1: Topical Talk
Montag, 23. März 2009, 15:30–16:00, GER 38
Theory of carrier dynamics in quantum dot light emitters — •Ermin Malic1, Marten Richter1, Jeong-Eun Kim1, Janik Wolters1, Matthias-Rene Dachner1, Ulrike Woggon2, and Andreas Knorr1 — 1Institut für Theoretische Physik, Technische Universität Berlin — 2Institut für Optik und Atomare Physik, Technische Universität Berlin
We present a microscopic theory describing the charge carrier dynamics in quantum dot light emitters, such as lasers and amplifiers. The theoretical approach is based on quantum dot Bloch equations including microscopically calculated Coulomb and electron-phonon scattering rates between bound quantum dot, continuous wetting layer, and bulk states. After electrical injection of charge carriers, their subsequent transfer from bulk into the wetting layer and quantum dot is considered via phonon induced relaxation processes. The latter generate hot non-equilibrium carriers. As a result the electronic temperature is increased. At high charge carrier densities, Coulomb scattering modifies the picture. Here, we focus on two typical aspects: i) Gain dynamics of QD amplifiers at high electrical injection, ii) Switch-on dynamics of QD-VCELS and edge emitters.
We discuss the importance of the interplay between scattering contributions and induced emission and absorption processes on the device properties. These investigations are performed at different temperatures, for different density regimes, and for various pulse areas.