Graphene has attracted much attention for the realization of high-speed photodetection for silicon photonics over a wide wavelength range. However, the reported fast graphene photodetectors mainly operate in the 1.55 μm wavelength band. In this work, we propose and realize high-performance waveguide photodetectors based on bolometric/photoconductive effects by introducing an ultrathin wide silicon−graphene hybrid plasmonic waveguide, which enables efficient light absorption in graphene at 1.55 μm and beyond. When operating at 2 μm, the present photodetector has a responsivity of ~70 mA/W and a setup-limited 3 dB bandwidth of >20 GHz. When operating at 1.55 μm, the present photodetector also works very well with a broad 3 dB bandwidth of >40 GHz (setup-limited) and a high responsivity of ~0.4 A/W even with a low bias voltage of −0.3 V. This work paves the way for achieving high-responsivity and high-speed silicon–graphene waveguide photodetection in the near/mid-infrared ranges, which has applications in optical communications, nonlinear photonics, and on-chip sensing.

石墨烯在实现宽波长范围内的硅光子学高速光电检测方面引起了广泛关注。但是，已报道的快速石墨烯光电探测器主要在1.55μm波段工作。在这项工作中，我们提出并实现了一种基于辐射热/光电导效应的高性能波导光电探测器，方法是引入超薄的宽硅-石墨烯杂化等离子体波导，该波导能够在1.55μm及以上的石墨烯中有效吸收光。当以2μm工作时，本光电探测器的响应度约为70 mA / W，设置受限的3 dB带宽> 20 GHz。当工作在1.55μm时，即使在-0.3 V的低偏置电压下，本光电探测器也可以在> 40 GHz的3dB宽带宽（设置受限）和〜0.4 A / W的高响应度下表现出色。