Dual‐Mode Switching of Photodetection and Neuromorphic Photoelectric Memory in V _S ‐ReS ₂ /WSe ₂ Heterostructure via Vacancy and Electric Field Synergetic Regulation

Abstract Integrating photodetection and photoelectric memory functions into a single device, which enables high‐efficiency signal processing and chip miniaturization, faces a great challenge due to the inherent speed discrepancy in their photoresponse characteristics. Herein, it is demonstrated the dual‐mode switching of photodetection and neuromorphic photoelectric memory in a V _S ‐ReS ₂ /WSe ₂ heterostructure. The sulfur vacancies (V _S ) in ReS ₂ induced by strong light irradiation together with the electric field can synergistically modulate the carrier transport in the heterostructure device. As result, under negative bias voltage, the device exhibits a photodetection function with ultrafast response speed (τ _rise = 6.63 µs, τ _decay = 6.28 µs) and strong polarization‐dependence (anisotropy ratio: 4.0), which enables the device novel photoelectric logic outputs of “AND” and “OR” as well as high‐resolution image sensing. Under positive bias voltage, the device exhibits a photoelectric memory function with fast optical writing and electrical erasing operations. The memory device can control and stabilize more than 128 operating states (7‐bit), and it displays an over 10 years retention time. Furthermore, based on the dual‐mode switching, the detection, memory, and recognition of handwritten digit images are completed in a single device. This work sheds light on the construction of novel multifunctional 2D optoelectronic devices for applications in artificial intelligence.