Dresden 2026 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 17: Quantum Dots and Wires: Rings, Wires and Transport
HL 17.5: Vortrag
Dienstag, 10. März 2026, 10:30–10:45, POT/0251
Improving optical quality in highly strained GaAs/InxAl1−xAs core/shell nanowires — Xiaoxiao Sun, •Alexej Pashkin, René Hübner, Finn Moebus, Yuxuan Sun, Andreas Worbs, Slawomir Prucnal, Shengqiang Zhou, Stephan Winnerl, Manfred Helm, and Emmanouil Dimakis — Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
III-V semiconductor nanowires are promising for applications in photonics, electronics, and sensing. In lattice-mismatched GaAs/InxAl1−xAs core/shell nanowires, tensile strain in the GaAs core enables substantial bandgap tuning across the near-infrared spectrum. However, InxAl1−xAs shells are typically grown at low temperatures, which compromises their structural quality and induces non-radiative recombination. We present two strategies to mitigate it. The first employs a dual-shell architecture in which an intermediate AlyGa1−yAs shell spatially separates carriers in the GaAs core from the InxAl1−xAs shell [1]. Optimizing the spacer thickness significantly enhances photoluminescence efficiency and extends emission lifetimes. The second strategy focuses on optimizing the shell growth conditions. We show that higher growth temperatures improve the core/shell interface quality, reducing non-radiative recombination and carrier scattering, with optimal performance near 500∘C [2]. This allows a simple single-shell structure to approach the performance of the more complex dual-shell design.
[1] X. Sun et al., Adv. Funct. Mater. 34, 2400883 (2024).
[2] X. Sun et al., Appl. Phys. Lett. 127, 182107 (2025).
Keywords: Nanowires; Epitaxy; Time-resolved photoluminescence; Crystallographic defects; Charge recombination