Regensburg 2022 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 12: Quantum Dots and Wires 3: Growth

HL 12.1: Hauptvortrag

Dienstag, 6. September 2022, 09:30–10:00, H32

Wafer-Scale Epitaxial Modulation of Quantum Dot Densitiy — •Nikolai Bart¹, Christian Dangel², Peter Zajac¹, Nikolai Spitzer¹, Marcel Schmidt¹, Kai Müller^2,3, Andreas D. Wieck¹, Jonathan Finley², and Arne Ludwig¹ — ¹Ruhr-Universität Bochum, Lehrstuhl für Angewandte Festkörperphysik, Universitätsstraße 150, 44801 Bochum, Germany — ²Walter Schottky Institut and Physik Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany — ³Walter Schottky Institut and Department of Electrical and Computer Engineering, Technische Universität München, 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 (PL) 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).