Graphene-Antenna Sandwich Photodetector
Graphene-Antenna Sandwich Photodetector
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DOI：
10.1021/nl301774e
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发表时间：
2012-07-01
期刊：
影响因子：
10.8
通讯作者：
Halas, Naomi J.
中科院分区：
文献类型：
--
作者：
Fang, Zheyu;Liu, Zheng;Halas, Naomi J.
夹在两个石墨烯单层之间的纳米级天线产生光电检测器，该光电检测器有效地将可见光和近红外光子转换为电子，相对于无天线石墨烯器件，光电流增强800%。天线以两种方式对光电流做出贡献：通过等离子体衰变时在天线结构中产生的热电子的转移，以及由于天线近场导致的固有石墨烯电子的直接等离子体增强激发。这导致基于石墨烯的光电探测器在光谱的可见光和近红外区域中实现高达20%的内部量子效率。该器件可以作为一个模型，用于将光频天线的光捕获特性与石墨烯在新光电器件中的高度吸引人的传输特性相结合。
Nanoscale antennas sandwiched between two graphene monolayers yield a photodetector that efficiently converts visible and near-infrared photons into electrons with an 800% enhancement of the photocurrent relative to the antennaless graphene device. The antenna contributes to the photocurrent in two ways: by the transfer of hot electrons generated in the antenna structure upon plasmon decay, as well as by direct plasmon-enhanced excitation of intrinsic graphene electrons due to the antenna near field. This results in a graphene-based photodetector achieving up to 20% internal quantum efficiency in the visible and near-infrared regions of the spectrum. This device can serve as a model for merging the light-harvesting characteristics of optical frequency antennas with the highly attractive transport properties of graphene in new optoelectronic devices.