Infrared photodetectors are currently subject to a rapidly expanding application space, with an increasing demand for compact, sensitive and inexpensive detectors. Despite continued advancement, technological factors limit the widespread usage of such detectors, specifically, the need for cooling and the high costs associated with processing of iii–v/ii–vi semiconductors. Here, black phosphorous (bP)/MoS₂ heterojunction photodiodes are explored as mid-wave infrared (MWIR) detectors. Although previous studies have demonstrated photodiodes using bP, here we significantly improve the performance, showing that such devices can be competitive with conventional MWIR photodetectors. By optimizing the device structure and light management, we demonstrate a two-terminal device that achieves room-temperature external quantum efficiencies (η_e) of 35% and specific detectivities (D*) as high as 1.1 × 10¹⁰ cm Hz^1/2 W⁻¹ in the MWIR region. Furthermore, by leveraging the anisotropic optical properties of bP we demonstrate the first bias-selectable polarization-resolved photodetector that operates without the need for external optics.

红外光电检测器目前正在迅速扩大应用空间，对紧凑，灵敏和便宜的检测器的需求也在增加。尽管取得了持续的进步，但技术因素仍然限制了此类检测器的广泛使用，特别是冷却需求以及与iii – v / ii – vi半导体处理相关的高成本。在此，黑磷（bP）/ MoS ₂异质结光电二极管被用作中波红外（MWIR）检测器。尽管先前的研究已经证明了使用bP的光电二极管，但在这里我们可以显着提高性能，表明此类设备可以与常规MWIR光电探测器竞争。通过优化该器件结构和光管理，我们表明，达到室温外部量子效率的两终端设备（η _Ë的35％）和特定探测率（d *）高达1.1×10 ¹⁰ 厘米赫兹^1/2  W ^-1在MWIR地区。此外，通过利用bP的各向异性光学特性，我们展示了无需外部光学器件即可运行的第一个偏置可选的偏振分辨光电探测器。