Mid‐Infrared nW‐level 2D Van der Waals Photodetector for Centimeter‐Precision Distance Sensing

Abstract Realizing weak‐light spectral resolution and pixel‐level adaptive distance detection in the mid‐wavelength infrared (MWIR) regime represents a critical step toward multifunctional integration and depth estimation in infrared imaging under complex environmental conditions. However, conventional infrared photodetection technologies are fundamentally limited in their ability to simultaneously support multispectral infrared detection window and spatial distance sensing at the device level. In this work, a novel 2D MWIR photodetector (PD) is designed and realized using a 2H‐MoTe 2 /PdSe 2 van der Waals heterojunction (vdWH), which for the first time achieves the dual functions of broad spectral‐resolved weak‐light detection in a waveband covering 2.65–7.05 µm and pixel‐level object‐spacing detection with centimeter‐level accuracy at a single device level. The device exhibits an ultralow noise equivalent power ( NEP ) on the order of 10 −13 W Hz −1/2 and maintains an effective ranging window range up to 19.5 cm. Furthermore, this work proposes a pixel‐level distance reconstruction method based on single‐point photocurrent and image brightness observation. By integrating spectrally adaptive modeling and nonlinear algorithmic optimization, the method effectively suppresses noise interference and significantly enhances 3D perception adaptability under low‐light conditions, offering a new pathway for precise infrared sensing and spatial information acquisition in complex environments.