Self‐Powered NbTe 2 /MoS 2 Photodetectors With High‐Sensitivity for Potential Intelligent Underwater Imaging Applications

Underwater optical imaging, vital for marine exploration, faces the challenge of optical signal degradation caused by water absorption and scattering, necessitating photodetectors with high sensitivity and low noise. In this work, we report a vertically stacked two‐dimensional NbTe 2 /MoS 2 van der Waals heterojunction designed for self‐powered underwater photodetection. Owing to the strong built‐in electric field at the heterointerface, the device effectively suppresses dark current and achieves a high rectification ratio of 7.3 × 10 4 . The photodetector exhibits a self‐powered, broadband photoresponse spanning the visible to near‐infrared region, with a peak responsivity of 2.1 mA/W and a specific detectivity of 6.7 × 10 10 Jones at 405 nm, outperforming most reported self‐powered heterojunction photodetectors. Under reverse bias, the detectivity is further enhanced to 1.15 × 10 12 Jones due to the strengthened internal electric field. Additionally, the device demonstrates a rapid temporal response, featuring a rise time of ≈47 µs and a decay time of ≈52 µs, respectively. Notably, the NbTe 2 /MoS 2 photodetector exhibits high imaging fidelity in aquatic environments, enabling high‐definition imaging through a deep‐learning‐based restoration algorithm. These results position the NbTe 2 /MoS 2 heterojunction as a promising candidate for energy‐efficient, high‐sensitivity underwater optoelectronics, advancing the field of intelligent underwater imaging.