Promoting Two-Dimensional Photodetectors Using a Plasmonic Nanofilm with an Ultrabroad Enhancement Band beyond 1700 nm in the Visible–NIR Range

Photodetectors based on two-dimensional (2D) materials have attracted significant attention due to their high sensitivity, fast response, room-temperature operation, and so on. However, one of its major challenges is achieving broadband photodetection with high performance across different wavelength ranges. Here, we present an approach to construct plasmon-enhanced 2D photodetectors with ultrabroadband enhancement beyond 1700 nm, covering the visible and near-infrared spectrum. The as-constructed plasmonic 2D photodetectors support detectivity higher than 1014 Jones and responsivity near or exceeding 104 A/W over a spectral range exceeding 400 nm, which surpasses previous reports of visible and near-infrared 2D photodetectors. In addition, the used plasmonic nanostructure can be directly fabricated via sputtering without complex patterning processes, making it scalable and efficient to construct broadband plasmonic 2D photodetectors. With the notable performance in broadband photodetection, the presented approach offers a promising route for high-performance broadband 2D photodetectors and boosts their development in real-world applications.