Berlin 2005 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 55: Quantenpunkte und -dr
ähte: Herstellung und Charakterisierung II

HL 55.2: Vortrag

Dienstag, 8. März 2005, 15:15–15:30, TU P-N201

Aligned InAs quantum dots grown on an epitaxially patterned (110) GaAs surface — •Jochen Bauer, Dieter Schuh, Emanuelle Uccelli, Robert Schulz, Max Bichler, Jonathan Finley, and Gerhard Abstreiter — Walter Schottky Institut, Technische Universität München, Am Coulombwall 3, D-85748 Garching

The control of the position of quantum dots is an important demand for the use of quantum dots in future devices and can e.g. be achieved by lithographic methods. A new approach is to self-align InAs quantum dots on defined positions on a (110) GaAs surface as recently demonstrated [1]. Here the template to determine the position of the quantum dots is fabricated using the cleaved edge overgrowth technique (CEO): In a 1st growth step, a series of AlAs layers is grown with molecular beam epitaxy (MBE) on (001) GaAs. By in situ cleaving this substrate, a smooth (110) GaAs surface with alternating GaAs and AlAs stripes is obtained. The subsequent deposition of InAs on this surface leads to the formation of InAs quantum dots on top of the AlAs stripes. Due to the high precision of MBE, an atomically precise positioning of these quantum dot chains is possible. Futhermore the size of the quantum dots is correlated with the thickness of the AlAs-stripes, and, hence, can be adjusted in the first MBE growth step. Therefore also the emission energy of these dots is adjustable and µ-PL investigations demonstrate the good optical qualities of these quantum dots.

[1] J. Bauer et al., Appl. Phys. Lett. 85, 4750(2004)