Regensburg 2004 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 42: Quantenpunkte und -dr
ähte: Optische Eigenschaften II
HL 42.4: Vortrag
Donnerstag, 11. März 2004, 16:00–16:15, H13
Excitonic Complexes in Single InGaN Quantum Dots — •Robert Seguin1, Sven Rodt1, Andre Strittmatter1, Dieter Bimberg1, Eike Hahn2, and Dagmar Gerthsen2 — 1TU Berlin, Institut für Festkörperphysik, Sekr. PN 5-2, Hardenbergstr. 36, D-10623 Berlin, Germany — 2Laboratorium für Elektronenmikroskopie, Universität Karlsruhe, D-76128 Karlsruhe, Germany
InGaN quantum dots (QDs) are very promising for future light emitting devices covering the visible region. But little is known about their electronic structure like excitonic complexes.
We present results obtained by cathodoluminescence spectroscopy on single InGaN/GaN QDs grown by MOCVD on Silicon(111) substrate. To probe single QDs metallic shadow masks are evaporated onto the sample surface. The QDs consist of In-rich regions within an inhomogenous InGaN layer, as is demonstrated by high-resolution cross-section transmission electron microscopy. The existence of zero-dimensional localization centers is confirmed by the observation of δ-function like emission lines at low temperatures and temperature dependent measurements.
The spectral jitter [1] of the various emission lines, enables us to identify up to 5 lines originating from the same QD. Excitation density and polarization dependent measurements reveal more information about the electronic origin of these lines.
[1] V. Türck, S. Rodt, R. Heitz, O. Stier, M. Straßburg, U.W. Pohl, and D. Bimberg, Physica E 13, 269 (2002).