Berlin 2018 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 4: Quantum dots and wires: Optical properties I
HL 4.2: Vortrag
Montag, 12. März 2018, 09:45–10:00, EW 201
InP-based coupled quantum well - quantum dot structures for 1.55 µm high speed laser applications — •Sven Bauer1, Vitalii Sichkovskyi1, Wojciech Rudno-Rudziński2, Grzegorz Sek2, and Johann Peter Reithmaier1 — 1Technische Physik, Institute of Nanostructure Technologies and Analytics (INA), CINSaT, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany — 2Institute of Physics, Wrocław University of Technology, Wybrzeze Wyspiańskiego 27, 50-370 Wrocław, Poland
The performance of directly modulated quantum dot (QD) lasers, used for 1.55 µm telecommunication, is limited by the intraband carrier relaxation time. To improve it, one might use a so called tunnel injection (TI) scheme. Carriers are captured and relax in a quantum well (QW) and tunnel through a thin barrier for recombination into the QDs. In order to get a better understanding of the involved mechanisms, coupled QW-QD structures have been grown on Fe-doped InP substrates. These consist of a InGaAs QW, a thin InAlGaAs barrier, both lattice matched to InP, and InAs QDs. Samples with varying QW and barrier thicknesses were grown, in order to determine the best TI structure candidate to implement into a high speed QD laser design. These were investigated with photoluminescence and photoreflectance spectroscopy. Atomic force microscopy was used to determine the influence of the QD morphology on their emission behavior. The influence of the band alignment and coupling strength on the emission behavior could be shown. An incorporation of the optimum TI structure into an actual laser design showed promising properties.