Solution-Grown Nanowire Devices for Sensitive and Fast Photodetection.
Solution-Grown Nanowire Devices for Sensitive and Fast Photodetection.
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DOI：
10.1021/acsami.5b02547
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发表时间：
2015-06
影响因子：
9.5
通讯作者：
Alexander Littig;Hauke Lehmann;C. Klinke;T. Kipp;A. Mews
中科院分区：
文献类型：
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作者：
Alexander Littig;Hauke Lehmann;C. Klinke;T. Kipp;A. Mews
利用电化学法和湿化学法的优点，研制出了以CdSe量子纳米线为活性元件的高灵敏、快速的光电探测器。直接在交错的铂电极上电化学合成的铋纳米粒子在接下来的溶液中用作催化剂-在温和的条件下，低温下直接在浸泡的衬底上液-固合成量子纳米线。这种快速而简单的制备过程导致了一种光电探测器装置，其具有一层有限厚度的纳米线薄膜来桥接电极间隙，其中高比例的单个纳米线被电接触并同时暴露在光中。光电探测器器件的高灵敏度可以通过其通断比或在长达约700 nm的宽波长范围内的光敏性大于10(7)来表示。测得比探测率D*=4×10(13)琼斯，响应率R=0.32A/W。该器件的速度反映在高于1 MHz的3分贝频率中，对应于350 ns以下的上升和下降时间。高灵敏度和快速响应的显著结合归因于纳米线内部的耗尽区、纳米线之间的隧道结势垒和电极上的肖特基接触，所有这些特征都强烈地受到光生载流子数量的影响。
Highly sensitive and fast photodetector devices with CdSe quantum nanowires as active elements have been developed exploiting the advantages of electro- and wet-chemical routes. Bismuth nanoparticles electrochemically synthesized directly onto interdigitating platinum electrodes serve as catalysts in the following solution-liquid-solid synthesis of quantum nanowires directly on immersed substrates under mild conditions at low temperature. This fast and simple preparation process leads to a photodetector device with a film of nanowires of limited thickness bridging the electrode gaps, in which a high fraction of individual nanowires are electrically contacted and can be exposed to light at the same time. The high sensitivity of the photodetector device can be expressed by its on/off ratio or its photosensitivity of more than 10(7) over a broad wavelength range up to about 700 nm. The specific detectivity and responsivity are determined to D* = 4 × 10(13) Jones and R = 0.32 A/W, respectively. The speed of the device reflects itself in a 3 dB frequency above 1 MHz corresponding to rise and fall times below 350 ns. The remarkable combination of a high sensitivity and a fast response is attributed to depletion regions inside the nanowires, tunnel-junction barriers between nanowires, and Schottky contacts at the electrodes, where all of these features are strongly influenced by the number of photogenerated charge carriers.