Although outstanding detectivities, InGaAs photodetectors for optic fiber communication are often costly due to the need for cooling. Therefore, cryogen-free and cost-effective alternatives working in telecommunication bands are highly desired. Here, we present a design of hot-electron photodetectors (HE PDs) with attributes of room-temperature operation and strong optical absorption over S and C bands (from 1460 to 1565 nm). The designed HE PD consists of a metal–semiconductor–metal hot-electron stack integrated with a front grating. Optical simulations reveal that mode hybridizations between Fabry–Pérot resonance and grating-induced surface plasmon excitation lead to high absorption efficiencies (≥0.9) covering S and C bands. Probability-based electrical calculations clarify that device responsivity is mainly determined by working wavelength on the premise of broadband strong absorption. Moreover, through comparison studies between the grating-assisted HE PD and purely planar microcavity system that serves as a reference, we highlight the design superiorities in average absorption and average responsivity with optimized values of 0.97 and 0.73 mA W⁻¹, respectively. The upgraded peformances of the designed device are promising for efficient photoelectric conversion in optic fiber communication systems.

中文翻译：

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用于 S 和 C 波段电信的光栅辅助热电子光电探测器

尽管具有出色的探测能力，但用于光纤通信的 InGaAs 光电探测器由于需要冷却而通常成本高昂。因此，非常需要在电信频段工作的无制冷剂且具有成本效益的替代方案。在这里，我们提出了一种热电子光电探测器 (HE PD) 的设计，该探测器具有室温工作特性以及 S 和 C 波段（1460 至 1565 nm）的强光吸收特性。设计的 HE PD 由与前光栅集成的金属-半导体-金属热电子堆栈组成。光学模拟表明，法布里-珀罗共振和光栅诱导的表面等离子体激发之间的模式杂化导致覆盖 S 和 C 波段的高吸收效率 (≥0.9)。基于概率的电学计算表明，在宽带强吸收的前提下，器件响应度主要由工作波长决定。此外，通过光栅辅助HE PD和作为参考的纯平面微腔系统之间的比较研究，我们强调了平均吸收率和平均响应率的设计优势，优化值分别为0.97和0.73 mA W ^-1。所设计器件的升级性能有望在光纤通信系统中实现高效光电转换。