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arXiv · 1511.04962

Ultrafast photodetection in the quantum wells of single AlGaAs/GaAs-based nanowires

Nadine Erhard·Stefan Zenger·Stefanie Morkötter·Daniel Rudolph·Matthias Weiss·Hubert J. Krenner·Helmut Karl·Gerhard Abstreiter·Jonathan J. Finley·Gregor Koblmüller·Alexander W. Holleitner
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Abstract

We investigate the ultrafast optoelectronic properties of single Al0.3Ga0.7As/GaAs-core-shell-nanowires. The nanowires contain GaAs-based quantum wells. For a resonant excitation of the quantum wells, we find a picosecond photocurrent which is consistent with an ultrafast lateral expansion of the photogenerated charge carriers. This Dember-effect does not occur for an excitation of the GaAs-based core of the nanowires. Instead, the core exhibits an ultrafast displacement current and a photo-thermoelectric current at the metal Schottky contacts. Our results uncover the optoelectronic dynamics in semiconductor core-shell nanowires comprising quantum wells, and they demonstrate the possibility to use the low-dimensional quantum well states therein for ultrafast photoswitches and photodetectors.

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Nadine Erhard, Stefan Zenger, Stefanie Morkötter, Daniel Rudolph, Matthias Weiss, Hubert J. Krenner, Helmut Karl, Gerhard Abstreiter, Jonathan J. Finley, Gregor Koblmüller, Alexander W. Holleitner. 2015-11-16. Ultrafast photodetection in the quantum wells of single AlGaAs/GaAs-based nanowires. https://doi.org/10.1021/acs.nanolett.5b02766

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