Van der Waals integration of 2D single-crystal transporter with quantum dots for scalable SWIR image sensors

Short-wave infrared imaging holds transformative potential in semiconductor inspection, biomedical diagnostics, and autonomous driving. However, its broad adoption is hindered by the high cost of incumbent technologies such as InGaAs. Colloidal quantum dots (CQDs) offer spectral tunability and low-cost processing, yet they face a fundamental bottleneck when extending to longer wavelengths: increased quantum-dot size degrades the interface with conventional transport layers (e.g. EDT), leading to surging dark current and deteriorated signal-to-noise ratio. Here, we propose a new interfacial-engineering strategy to overcome this challenge. We design the 2D Bi₂O₂Te/PbS CQD heterojunction exhibiting an atomically flat interface and optimized band alignment, reducing the interfacial defect density by an order of magnitude. Based on this architecture, we fabricate high-performance infrared photodetectors that, at 1.7 µm, simultaneously achieve a record-low dark-current density (98 nA cm^-2), high external quantum efficiency (74%), and high specific detectivity (4.6 × 10¹² Jones). Furthermore, we successfully scale the process to produce a fully monolithic focal-plane array with a 5 µm pixel pitch and a format of 1920 × 1536, demonstrating exceptional imaging capabilities in complex scenarios such as silicon-transparent imaging, haze-penetrating vision, and moisture identification. This work not only provides a viable route to low-cost, high-performance SWIR imaging but, more importantly, establishes a general paradigm for precisely tailoring nano-crystal optoelectronic interfaces using 2D single crystals, opening a new pathway for the design of next-generation on-chip spectral-sensing systems.