Ultrafast Photodetection in the Quantum Wells of Single AlGaAs/GaAs-Based Nanowires
Ultrafast Photodetection in the Quantum Wells of Single AlGaAs/GaAs-Based Nanowires
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DOI：
10.1021/acs.nanolett.5b02766
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发表时间：
2015-10-01
期刊：
影响因子：
10.8
通讯作者：
Holleitner, A. W.
中科院分区：
文献类型：
--
作者：
Erhard, N.;Zenger, S.;Holleitner, A. W.
研究了单根Al_（0.3）Ga_（0.7）As/GaAs核壳纳米线的超快光电特性。纳米线包含GaAs基量子威尔斯。对于量子威尔斯的共振激发，我们发现一个皮秒光电流，这是一致的光生载流子的超快横向膨胀。这种登伯效应不会发生的GaAs基的纳米线的核心的激发。相反，核心表现出超快位移电流和光热电电流在金属肖特基接触。我们的研究结果揭示了半导体核壳纳米线包括量子威尔斯的光电动力学，他们证明了使用低维量子阱态的超快光电开关和光电探测器的可能性。
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 photothermoelectric 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.