Low Noise Mixed-Dimensional Uncooled PbSe/InSe/Bi ₂ Se ₃ van der Waals Barrier Infrared Detector

The performance of unipolar barrier infrared photodetectors is often limited by interfacial defects in conventional lattice-mismatched epitaxial heterojunctions. Here, we overcome this challenge by constructing a mixed-dimensional van der Waals barrier heterostructure (PbSe/InSe/Bi 2 Se 3 ), where a two-dimensional InSe layer serves as a hole barrier to suppress the room temperature dark current effectively. This barrier detector exhibits an extremely low dark current of 6.7 × 10 –11 A and noise-equivalent power of 4.717 × 10 –13 W/Hz 1/2 at room temperature. Furthermore, this unipolar barrier detector demonstrates outstanding detectivity of 6.16 × 10 9 Jones under 2.7 μm illumination at room temperature. The successful realization of this mixed-dimensional unipolar barrier detector highlights the significant potential of epitaxial PbSe combined with two-dimensional materials for high-performance room temperature infrared detection and offers a promising pathway for industrial-scale fabrication of sensitive infrared photodetectors.