Ferroelectrically‐Controlled Multi‐State Switching in AgVP ₂ S ₆ /WSe ₂ van der Waals Heterojunctions for Efficient Visible‐To‐Near‐Infrared Photodetection

Abstract 2D van der Waals (2D vdW) ferroelectric heterojunctions hold promise for advancing optoelectronic technologies. However, several challenges remain, such as carrier recombination and tunability. Here, AgVP 2 S 6 is introduced, a p ‐type ferroelectric semiconductor with a small bandgap of 0.43 eV, and designs a ferroelectrically controlled AgVP 2 S 6 /WSe 2 heterojunction photodetector. The type‐I band alignment enables the AgVP 2 S 6 layer to efficiently extract photogenerated electrons from WSe 2 , suppressing interfacial recombination and enhancing responsivity across visible to near‐infrared wavelengths. Particularly, the device exhibits three non‐volatile photoresponse states, rapidly switchable via ferroelectric polarization, showcasing reconfigurability in self‐powered photodetection. This work provides a pathway toward adaptive, multi‐functional optoelectronics for intelligent photodetection, infrared sensing, and optical memory applications.