Regensburg 2010 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 13: Quantum Dots and Wires: Preparation and Characterization I

HL 13.4: Talk

Monday, March 22, 2010, 14:45–15:00, H17

Influence of arsenic species on InAs island formation on InAlGaAs/InP (100 ) surfaces — •Christian Gilfert¹, Emil-Mihai Pavelescu², and Johann Peter Reithmaier¹ — ¹Technische Physik, Institut für Nanostrukturtechnologie und Analytik, Universität Kassel, 34132 Kassel, Germany — ²National Institute for Research and Development in Microtechnologies, 077190 Bucharest, Romania

The nucleation of InAs on InP(100) is far more complex than in the In(Ga)As/GaAs system and a variety of different structures has been reported. However, optoelectronic devices such as semiconductor lasers and amplifiers for 1.3 µ m and 1.55 µ m require a well established electronic confinement of the charge carriers for improved device performance in terms of, e.g., threshold current and temperature stability. Therefore, homogenously grown round-shaped quantum dots are the structures of choice, since they present a zero-dimensional system for the carriers. Round-shaped quantum dots on InP were accomplished by several growth methods. To the best of the authors‘ knowledge a study of the influence of the arsenic species on the nucleation of InAs has not been reported yet. We demonstrate that the arsenic species has quite a dramatic impact. When supplying As₂ the deposited InAs preferentially forms round-shaped quantum dots, which exhibit an improved photoluminescence over the As₄ counterparts. FWHM values as low as 22 meV at 10 K were achieved. This linewidth is smaller than state-of-the-art linewidth reported yet for InAs quantum dots grown on InAlGaAs/InP(100) based compounds.