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HL: Fachverband Halbleiterphysik
HL 41: Quantum dots and wires: Preparation and characterization
HL 41.4: Vortrag
Dienstag, 12. März 2013, 12:00–12:15, H15
High density (Ga,In)As/GaP self-assembled quantum dots — •Matthias Heidemann, Sven Höfling, and Martin Kamp — Technische Physik and Wilhelm-Conrad-Röntgen-Research Center for Complex Material Systems, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
The large lattice mismatch between usual III/V materials and Si is one of the most important issues considering defect-free nucleation of layer structures for monolithic integration with Si CMOS technology. Among the III/V materials, GaP offers the lowest lattice mismatch to Si with only 0.37% at 300K and the incorporation of 2% nitrogen results in a perfect lattice match to Si. Since GaP has an indirect bandgap, a direct bandgap III/V material epitaxially grown on GaP is required and various materials and nanostructures have been proposed. Dilute Nitride Materials are used to enhance the direct bandgap character in GaAsPN/GaP and GaInPN/GaP quantum wells. By using quantum dots (QDs) the growth of larger lattice-mismatched nano-structures is possible, resulting in a direct bandgap without the incorporation of nitrogen.
In this work self-assembled InGaAs QDs embedded in GaP have been grown using molecular beam epitaxy. Based on these QDs, light emitting diodes and laser structures were fabricated and characterized. The latest results show QDs with a high density of 8.2*1010 cm−2 and photo-/electroluminescence signal up to room temperature.