Graphene, a two-dimensional monatomic layer of carbon material, has demonstrated as a good candidate for applications of ultrafast photodetectors, transistors, transparent electrodes, and biosensors. Recently, many studies have shown that using metallic deep gratings could enhance the absorptance of graphene of 2.3% up to 80% in the near infrared region for applications in photon detection. This paper presents utilizing a nanograting structure, namely, a compound metallic grating could greatly enhance the absorptance of graphene up to 98% and widen its spectral bandwidth to 0.6 μm, which are greater than those of previous work. The study also showed that the absorptance spectrum is insensitive to angles of incidence. Furthermore, the proposed graphene-covered compound grating might bring a lot of benefits for graphene designs-based optical and optoelectronic devices.

中文翻译：

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石墨烯单层覆盖的金属复合光栅的超宽光谱带宽和增强吸收

石墨烯是一种二维单原子碳材料层，已被证明是超快光电探测器、晶体管、透明电极和生物传感器应用的良好候选材料。最近，许多研究表明，使用金属深光栅可以将石墨烯在近红外区域的吸收率提高 2.3% 至 80%，用于光子检测。本文提出了利用纳米光栅结构，即复合金属光栅可以大大提高石墨烯的吸收率高达 98%，并将其光谱带宽扩大到 0.6 μm，这比以前的工作更大。该研究还表明，吸收光谱对入射角不敏感。此外，