Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 10: Quantum Dots and Wires: Preparation and Characterization II (mainly Arsenides)

HL 10.6: Vortrag

Montag, 26. März 2012, 12:30–12:45, EW 202

MOVPE grown InAs quantum dots on InGaAs strain reducing layers — •Matthias Paul, Jan Kettler, Elisabeth Koroknay, Michael Jetter, and Peter Michler — Institut für Halbleiteroptik und Funktionelle Grenzflächen, University Stuttgart, Allmandring 3, 70569 Stuttgart, Germany

Self-assembled semiconductor quantum dots (QDs) have been studied extensively due to their potential application in the field of quantum information processing. Therefore, optically addressable single quantum dots are needed on a mass production scale using metal-organic vapor-phase epitaxy (MOVPE). By burying InAs QDs in InGaAs strain-reducing layers (SRL) their emission wavelength can be shifted to the infrared region. Of special interest are the telecom wavelength bands around 1.3 µm and 1.55 µm of optical fibers where losses are reduced to a minimum. In contrast to high densities for laser applications, low densities of QDs will allow for single-photon sources, one key device in quantum information networks. The approach pursued to reach emission wavelengths of 1.3 µm is depositing InAs QDs between two InGaAs SRLs grown on GaAs substrates. Reduced strain and increased QD size cause a red-shift of the emission wavelength. Photoluminescence (PL) experiments and scanning electron microcopy (SEM) are used to characterize the InGaAs layers. Furthermore, PL and µ-PL measurements are performed to investigate optical properties of the InAs QDs, as well as, atomic force microscopy (AFM) to determine structural properties, e.g. density and size.