Regensburg 2000 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 36: Quantenpunkte (Herstellung und Charakterisierung)
HL 36.4: Vortrag
Donnerstag, 30. März 2000, 16:45–17:00, H13
Near-field scanning optical spectroscopy of coupled quantum wire-dot structure — •F. Intonti1, V. Emiliani1, Ch. Lienau1, Th. Elsaesser1, J. Fricke2, R. Nötzel2, and K.H. Ploog2 — 1Max-Born-Institut, Max-Born-Str. 2A, 12489 Berlin — 2Paul-Drude-Institut, Hausvogteiplatz 5-7, 10117 Berlin
Quasi-one- or even quasi-zero-dimensional confinement of carriers in semiconductor heterostructures is achieved by lateral potential variations on the nanometer scale which are induced by growing quantum wells (QWs) on patterned substrates. Recently, a new growth mechanism has been found in molecular beam epitaxy of GaAs/(AlGa)As QW structures on stripe- patterned GaAs(311)A substrates. Quantum wires (QWRs) are formed due to the preferential migration of Ga ad-atoms from the mesa top and bottom towards one of the sidewalls of mesa stripes oriented along [01-1]. The combination of this growth mechanism with appropriate lithographic patterning of the sample surface allows the controlled fabrication of novel nanostructures. In particular, a quantum wire-dot structure has been realized by growth of a zigzag pattern with sidewalls alternating misaligned by + or - 300. Here, we report on the first low temperature near-field luminescence investigation of this novel coupled wire-dot structure, allowing the assignment of different optical transition energies to different spatial areas of the sample and demonstrating carrier transport along the QWR into the dot.