We report vertically illuminated, resonant cavity enhanced, graphene–Si Schottky photodetectors (PDs) operating at 1550 nm. These exploit internal photoemission at the graphene–Si interface. To obtain spectral selectivity and enhance responsivity, the PDs are integrated with an optical cavity, resulting in multiple reflections at resonance, and enhanced absorption in graphene. We get a wavelength-dependent photoresponse with external (internal) responsivity ∼20 mA/W (0.25A/W). The spectral selectivity may be further tuned by varying the cavity resonant wavelength. Our devices pave the way for developing high responsivity hybrid graphene–Si free-space illuminated PDs for optical communications, coherence optical tomography, and light-radars.

中文翻译：

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垂直照明，谐振腔增强的石墨烯-硅肖特基光电探测器

我们报告了在1550 nm下工作的垂直照明，谐振腔增强的石墨烯-Si肖特基光电探测器（PD）。它们利用了石墨烯-Si界面的内部光发射。为了获得光谱选择性并提高响应度，PD与光学腔集成在一起，从而在共振时产生多次反射，并增强了石墨烯的吸收。我们得到一个与波长有关的光响应，外部（内部）响应率为〜20 mA / W（0.25A / W）。可以通过改变腔谐振波长来进一步调谐光谱选择性。我们的设备为开发用于光通信，相干光学层析成像和光雷达的高响应性混合石墨烯-Si自由空间照明PD铺平了道路。