1. Ultrafast photodetection in the quantum wells of single AlGaAs/GaAs-based nanowires
- Author
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Erhard, Nadine, Zenger, Stefan, Morkötter, Stefanie, Rudolph, Daniel, Weiss, Matthias, Krenner, Hubert J., Karl, Helmut, Abstreiter, Gerhard, Finley, Jonathan J., Koblmüller, Gregor, and Holleitner, Alexander W.
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics - 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.
- Published
- 2015
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