Regensburg 2022 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 12: Quantum Dots and Wires 3: Growth

HL 12.2: Vortrag

Dienstag, 6. September 2022, 10:00–10:15, H32

Full Wafer Property Control of Local Droplet Etched GaAs Quantum Dots — •Hans-Georg Babin, Nikolai Bart, Marcel Schmidt, Nikolai Spitzer, Andreas D. Wieck, and Arne Ludwig — Ruhr-Universität Bochum, Deutschland

Local droplet etched GaAs quantum dots (LDE-QDs) are a promising candidate for excellent single and entangled photon sources [1]. It is important that the carefully developed and highly complex structures are matched perfectly with the embedded QDs [2]. In this submission, we show a way to control QD properties during molecular beam epitaxy on a single wafer, which opens the opportunity to find optimally fitting QDs for the desired experiments by just changing the position on the wafer.

We induce flux gradients by stopping sample rotation and using the parallax of the effusion-cells, resulting in a gradual change of deposited material and cell flux. By this we can vary properties of the QDs like density and emission wavelength on a single wafer. In this work, the widest achieved wavelength shift of the ground state emission energy at 100 K extends over the range of 795 nm to 737 nm [3]. The induced surface roughness modulation additionally induces a stripe-patterned modulation, which was shown before only with Stranski-Krastanov QDs [4].

[1] Huber, D. et al., Nat. Commun. 8 (1), S. 15506 (2017).

[2] Zhai, L. et al., Nat. Commun. 11 (1), S. 4745 (2020).

[3] Babin, H.G. et al., J. Cryst. Growth 591, S. 126713 (2022).

[4] Bart, N.; Dangel, C.; et al., Nat. Commun. 13, 1663 (2022).