Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 49: Quantum dots: preparation and characterization
HL 49.1: Vortrag
Freitag, 27. März 2009, 10:15–10:30, BEY 81
Growth and characterization of InP quantum dots deposited on InAs seed layer — •Daniel Richter, Robert Roßbach, Wolfang-Michael Schulz, Matthias Reischle, Claus Hermannstädter, Michael Jetter, and Peter Michler — Institut für Halbleiteroptik und Funktionelle Grenzflächen, Universität Stuttgart, Allmandring 3 70569 Stuttgart, Germany
As current single-photon detectors have their highest photon detection efficiency in the red spectral range it is preferable to fabricate single quantum dots (QD) with luminescence at such wavelengths.
Self assembled InP QDs emitting at around 670nm exhibit high densities up to 1*1010 cm−2. For single QD applications this density has to be reduced drastically. To achieve a low density of optical active InP QDs we used low density InAs islands as a seed layer.
We focus on the MOVPE growth of low density InAs quantum dots in the Stranski-Krastanow (SK) growth mode. An extensive characterization has been accomplished. Scanning electron microscopy measurements confirmed a QD density less than 1*107 cm−2 and atomic force microscopy was used to measure the height distribution. To complete the characterization optical measurements, like micro-photoluminescence (µ-PL) and ensemble PL have been performed. Equipped with the control over the InAs QD growth it is possible to use InAs QD-layers as seeds for the growth of InP QDs with a reduced density. Here we present the influence of the InAs seed layer on the InP QD density and their optical properties.