Position-sensitive detectors (PSDs) based on the lateral photo effect have been widely used in diverse applications including optical engineering, aerospace, and military fields. With increasing demands for long-working-distance, low-energy-consumption, and weak-signal-sensing systems, the poor responsivity of conventional silicon-based PSDs has become a bottleneck limiting their applications. Herein, we propose a high-performance passive PSD based on a graphene–Si heterostructure. The graphene is adapted as a photon-absorbing and charge-separation layer working together with Si as a junction, while the high mobility provides promising ultra-long carrier diffusion length and facilitates a large active area of the device. A PSD with a working area of $8\mathrm{mm}\times 8\mathrm{mm}$ is demonstrated to present excellent position sensitivity to weak light at the nanowatt level (much better than the limit of microwatts of Si P-I-N PSDs). More importantly, it shows very fast response and low degree of nonlinearity of $\sim 3\%$, and extends the operating wavelength to the near-infrared region (1319 and 1550 nm). This work therefore provides a new strategy for high-performance and broadband PSDs.

中文翻译：

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基于石墨烯-硅异质结的高性能位置感应探测器

基于横向光效应的位置敏感检测器（PSD）已广泛用于包括光学工程，航空航天和军事领域的各种应用中。随着对长距离工作，低能耗和弱信号感测系统的需求不断增加，常规的基于硅的PSD的较差的响应性已成为限制其应用的瓶颈。本文中，我们提出了一种基于石墨烯-Si异质结构的高性能无源PSD。石墨烯适合作为光子吸收和电荷分离层，并与硅作为结一起工作，而高迁移率提供了有希望的超长载流子扩散长度，并有利于器件的大有源区域。PSD的工作区域为$8\mathrm{毫米}\times 8\mathrm{毫米}$已证明在纳瓦级（弱于Si PIN PSD的微瓦限值）下，对弱光具有出色的位置灵敏度。更重要的是，它显示出非常快的响应速度和较低的非线性度$〜3％$，并将工作波长扩展到近红外区域（1319和1550 nm）。因此，这项工作为高性能和宽带PSD提供了新的策略。