An Advanced Robust van der Waals Heterostructure Photodetector with Ultralow Dark Current and a Large Linear Dynamic Range for Polarization Imaging and Optical Communication.

The diversity of 2D materials and their excellent optoelectronic properties have brought revolutionary opportunities and challenges for novel multifunctional semiconductor devices. As a representative multielement van der Waals semiconductor, AgInP2S6 offers a new platform for developing novel optoelectronic devices but suffers from bottlenecks including low response speed, narrow response spectrum, and single-functionality. Herein, an advanced robust ReSe2/AgInP2S6 vdWs heterostructure photodetector with a response spectrum spanning from the ultraviolet to near-infrared region was successfully constructed, enabling polarization-sensitive imaging and optical communication. An ultralow dark current (∼10-14 A), self-driven detection capability, large linear dynamic range (72.0 dB at 525 nm and 40.3 dB at 980 nm), long-term stable photoswitching operation, and fast response speed (rise/decay times: 170/150 μs) were achieved, facilitated by the efficient separation of photogenerated carriers within the built-in electric field at the heterointerface, as confirmed by high-spatial-resolution photocurrent mappings. Additionally, the heterostructure exhibits polarization-sensitive photodetection with dichroic ratios of 2.58 and 3.30 at 980 nm under self-powered and external bias-driven modes, respectively. This work establishes a novel strategy for developing high-performance, multifunctional photodetectors, enabling new design and application avenues for next-generation, advanced optoelectronic devices.