Self-Powered UV-NIR Polarization-Sensitive Photodetector Based on ReS₂/InSe van der Waals Heterostructure

van der Waals heterostructures (vdWHs) composed of two-dimensional (2D) van der Waals materials with in-plane optical anisotropy enable polarization-resolved detection, integrating polarized light detection and self-powered capability without external power sources, thereby achieving multifunctional detection. Here, we report a self-powered photodetector based on a 2D ReS2/InSe heterojunction, exhibiting an ultralow dark current of 5 × 10–14 A at zero bias. The device exhibits a distinct photovoltaic response, characterized by a 0.382 V open-circuit voltage and a 11 nA short-circuit current. Its specific detectivity reaches 4.45 × 1011 Jones, and a light on/off ratio of 2.2 × 105 under illumination with 405 nm laser. With fast response times (48/47 μs, rise/fall), the device achieves a broadband self-powered photoresponse spanning 365–1064 nm, with a polarization ratio of up to 1.3. Furthermore, this detector achieves synchronous detection of both visible light imaging and visible light communication. This work integrates broadband response, self-powered operation, and polarization-sensitive detection capabilities along with imaging and visible light communication functionality into a single photodetector, paving a promising pathway for next-generation multifunctional photodetectors.