Given the importance of the 0.1- to 1-THz range in the security detection and diagnosis of cancer, we propose a structure for graphene-based terahertz (THz) photodetectors. We use the finite-difference time-domain and mathematical methods to calculate the light absorption in the graphene layers (GLs) and the detector’s figure of merits, including responsivity and detectivity. The proposed photodetector is based on single-layer and multilayer graphene absorbers within a p-type-intrinsic-n-type (PIN) photodiode structure. This detector is designed to achieve maximum absorption at the THz frequencies by creating adjustable Fabry–Perot resonances. Results show that it has two distinct and adjustable detection peaks in THz. So we set the operating frequency to 0.35 and 0.83 THz by adjusting the geometric parameters of the device, which also fit the atmospheric windows. Despite the low number of GLs, high absorption is provided at room temperature. It has high responsivity peaks of ∼1220 AW − 1 at the frequency of 0.35 THz and 420 AW − 1 at 0.83 THz, respectively, while we have achieved these characteristics with fewer GLs than other previous detectors.

中文翻译：

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基于多石墨烯层吸收体的室温亚太赫兹PIN光电二极管光电探测器

鉴于 0.1 到 1-THz 范围在癌症安全检测和诊断中的重要性，我们提出了一种基于石墨烯的太赫兹 (THz) 光电探测器的结构。我们使用有限差分时域和数学方法来计算石墨烯层 (GL) 中的光吸收和探测器的品质因数，包括响应度和探测率。所提出的光电探测器基于 p 型本征 n 型 (PIN) 光电二极管结构内的单层和多层石墨烯吸收器。该检测器旨在通过产生可调节的法布里-珀罗共振在太赫兹频率处实现最大吸收。结果表明，它在太赫兹有两个不同且可调的检测峰。因此我们通过调整器件的几何参数将工作频率设置为 0.35 和 0.83 THz，这也适合大气窗户。尽管 GL 的数量很少，但在室温下提供了高吸收。它分别在 0.35 THz 和 420 AW - 1 的频率下具有 ∼1220 AW - 1 的高响应率峰值，在 0.83 THz 的频率下，而我们用比其他以前的探测器更少的 GL 实现了这些特性。