Suppression of alloy fluctuations in GaAs-AlGaAs core-shell nanowires
- Walter Schottky Institut and Physik Department, Technische Universität München, 85748 Garching (Germany)
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States)
- Department of Chemistry, Ludwig-Maximilians-Universität Munich, 81377 München (Germany)
Probing localized alloy fluctuations and controlling them by growth kinetics have been relatively limited so far in nanoscale structures such as semiconductor nanowires (NWs). Here, we demonstrate the tuning of alloy fluctuations in molecular beam epitaxially grown GaAs-AlGaAs core-shell NWs by modifications of shell growth temperature, as investigated by correlated micro-photoluminescence, scanning transmission electron microscopy, and atom probe tomography. By reducing the shell growth temperature from T > 600 °C to below 400 °C, we find a strong reduction in alloy fluctuation mediated sharp-line luminescence, concurrent with a decrease in the non-randomness of the alloy distribution in the AlGaAs shell. This trend is further characterized by a change in the alloy compositional structure from unintentional quasi-superlattices of Ga- and Al-rich AlGaAs layers at high T to a nearly homogeneous random alloy distribution at low T.
- OSTI ID:
- 22590469
- Journal Information:
- Applied Physics Letters, Vol. 109, Issue 9; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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