Regensburg 2004 – scientific programme

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HL: Halbleiterphysik

HL 44: Poster II

HL 44.77: Poster

Thursday, March 11, 2004, 16:30–19:00, Poster A

Local bandgap modulation of AlGaAs grown on patterned GaAs substrates — •Wolfgang Limmer, Karl Bitzer, and Rolf Sauer — Abteilung Halbleiterphysik, Universität Ulm, D-89069 Ulm

The growth of AlGaAs layers on patterned GaAs(001) substrates by molecular-beam epitaxy is strongly determined by the interfacet surface migration of Ga adatoms, leading to a pronounced variation of the local Al concentration. Taking advantage of this migration process, we have overgrown mesa structures, that consist of intersecting stripes or partially overlapping squares, to obtain a local maximum or minimum, respectively, of the AlGaAs bandgap on top of the mesas. While the surface morphologies were imaged by scanning electron microscopy, the local Al concentrations and thus the local AlGaAs bandgaps were mapped by spatially resolved micro-photoluminescence spectroscopy.