SKM 2023 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 42: Quantum dots: Growth
HL 42.5: Talk
Thursday, March 30, 2023, 16:30–16:45, POT 151
Wafer-Scale Epitaxial Modulation of Quantum Dot Densitiy — •Nikolai Bart1,2, Christian Dangel2, Peter Zajac1, Nikolai Spitzer1, Marcel Schmidt1, Kai Mueller2,3, Andreas D. Wieck1, Jonathan Finley2, and Arne Ludwig1 — 1Ruhr-Universitaet Bochum, Lehrstuhl fuer Angewandte Festkoerperphysik, Universitaetsstraße 150, 44801 Bochum, Germany — 2Walter Schottky Institut and Physik Department, Technische Universitaet Muenchen, Am Coulombwall 4, 85748 Garching, Germany — 3Walter Schottky Institut and Department of Electrical and Computer Engineering, Technische Universitaet Muenchen, Am Coulombwall 4, 85748 Garching, Germany
The effect of nanoscale surface roughness on the nucleation of self-assembled InAs quantum dots (QD) is investigated with photoluminescence spectroscopy and atomic force microscopy. We show in-situ control of the roughness modulation by common epitaxial layer-by-layer growth, leaving alternating atomically smooth (rough) surfaces for integer (fractional) completion of a monolayer. We report significant differences in both PL intensity and QD surface density at the critical threshold of nucleation. By varying the underlying GaAs thickness gradients, we create and control 1- and 2-dimensional density modulation patterns on entire 3-inch wafers with modulation periods between a few mm and down to hundreds of µm and densities between 1 and 10 QDs/µm2.
Bart, N., Dangel, C. et al. Wafer-scale epitaxial modulation of quantum dot density. Nat Commun 13, 1633 (2022).