Gold-patched graphene nano-stripes for high-responsivity and ultrafast photodetection from the visible to infrared regime
Gold-patched graphene nano-stripes for high-responsivity and ultrafast photodetection from the visible to infrared regime
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DOI：
10.1038/s41377-018-0020-2
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发表时间：
2018-06-20
影响因子：
19.4
通讯作者：
Jarrahi, Mona
中科院分区：
文献类型：
--
作者：
Cakmakyapan, Semih;Lu, Ping Keng;Jarrahi, Mona
石墨烯是一种非常有吸引力的高光谱成像和传感系统中的宽带光电探测材料。然而，它的潜在用途受到现有石墨烯光电探测器的响应度，带宽和操作速度之间的权衡的阻碍。在这里，我们提出了工程光导纳米结构的基础上金匹配的石墨烯纳米条纹，使同时宽带和超快的光电探测具有高响应度。这些纳米结构将石墨烯纳米带内的宽带光吸收、超快光载流子传输和载流子倍增的优点与光载流子在复合之前向金贴片的超快传输相结合。通过这种方法，实现了高响应度操作，而不使用带宽限制和速度限制量子点，缺陷态，或隧道势垒。我们展示了高sponsivity光电探测从可见光到红外制度（0.6 A/W在0.8 μ m和11.5 A/W在20 μ m），操作速度超过50 GHz。我们的研究结果表明，与基于量子点和隧穿势垒的高响应度石墨烯光电探测器相比，响应时间提高了7个数量级以上，带宽增加了1个数量级。
Graphene is a very attractive material for broadband photodetection in hyperspectral imaging and sensing systems. However, its potential use has been hindered by tradeoffs between the responsivity, bandwidth, and operation speed of existing graphene photodetectors. Here, we present engineered photoconductive nanostructures based on gold-atched graphene nano-stripes, which enable simultaneous broadband and ultrafast photodetection with high responsivity. These nanostructures merge the advantages of broadband optical absorption, ultrafast photocarrier transport, and carrier multiplication within graphene nano-stripes with the ultrafast transport of photocarriers to gold patches before recombination. Through this approach, high-responsivity operation is realized without the use of bandwidth-limiting and speed-limiting quantum dots, defect states, or tunneling barriers. We demonstrate high esponsivity photodetection from the visible to infrared regime (0.6 A/W at 0.8 mu m and 11.5 A/W at 20 mu m), with operation speeds exceeding 50 GHz. Our results demonstrate improvement of the response times by more than seven orders of magnitude and an increase in bandwidths of one order of magnitude compared to those of higher-responsivity graphene photodetectors based on quantum dots and tunneling barriers.