High‐Visibility Underwater Imaging Enabled by Schottky Barrier Engineering in Multilayer WS 2 Based Self‐Powered Blue‐Light Photodetector
Chuxin Yan, Chunyu Wang, Yuanzheng Li, Cheng Zhou, Qingbin Wang, Yongsheng Gao, Wei Xin, Weizhen Liu, Haiyang XuABSTRACT
Self‐powered blue‐light photodetectors, operating without an external power source, are highly desirable for low‐latency and interference‐resistant underwater wireless optical communication (UWOC). However, a key challenge persists in designing device architecture that provides a sufficiently strong built‐in electric field, limiting progress toward high‐performance self‐powered operation. Here, we address this challenge through Schottky barrier engineering at the interfaces, combined with multilayer WS 2 as the photosensitive layer that leverages high‐energy excitons for strong blue‐light absorption. The resulting PdSe 2 /WS 2 /graphene heterojunction photodetector exhibits a significantly enhanced built‐in electric field, yielding an ultrahigh responsivity of 214 mA/W and a high specific detectivity of 3 × 10 12 Jones. When integrated into a single‐pixel imaging system, the photodetector enables high‐visibility underwater imaging in both clear and turbid water environments, with the peak signal‐to‐noise ratio consistently maintained above 22 dB. This work introduces a new paradigm for self‐powered optoelectronic devices through Schottky barrier engineering and provides a foundation for next‐generation UWOC and real‐time underwater imaging systems.