Self-Driven PbI₂-Based Ultraviolet Photodetectors with Ultrafast Response

Fabricating self-driven UV detection photodetectors based on PbI2 materials remains a challenging issue due to chemical disorder and Fermi-level pinning. Here, we propose a self-driven PbI2-based ultraviolet photodetector, in which metal electrodes and graphene are prefabricated and physically laminated onto PbI2. The self-driven photodetector demonstrates an ultrafast response time (rise: 3.76, fall: 3.81 μs). Furthermore, the photodetector exhibits high responsivity (18.7 A/W), detectivity (1.56 × 1011 Jones), and external quantum efficiency (6206%). The excellent performance is attributed to the clean metal–semiconductor interface and the asymmetric heterojunction, which lead to a more efficient and faster collection of photogenerated carriers. These results highlight the potential of PbI2 for high-speed UV detection and propose an effective approach for improving 2D material-based photodetectors.