High-responsivity all-fiber self-powered photodetector based on Ti3C2Tx MXene/FA0.4MA0.6PbI3 heterojunction

Herein, an all-fiber integrated photodetector based on the Ti3C2Tx MXene/FA0.4MA0.6PbI3 heterojunction is proposed. The device utilizes side-polished optical fibers as the light transmission and structural integration platform, and achieves efficient separation of photogenerated carriers through the construction of a Type II bandgap arrangement heterojunction. Ti3C2Tx MXene leverages its high conductivity to accelerate carrier transport and suppress recombination, while FA0.4MA0.6PbI3 exhibits strong light absorption and high carrier generation efficiency. Their synergistic interaction significantly enhances the device's overall performance. Experimental results demonstrate that under 650 nm illumination, the device achieves a responsivity of 19.14 A/W in bias mode—seven times that of a single FA0.4MA0.6PbI3 device—with a response time of 16/24 ms, reduced by 8 ms compared to the single device. Benefiting from the high built-in electric field at the heterojunction interface, the device achieves self-driven operation, generating a photocurrent of 0.16 μA and a responsivity of 6.76 mA/W even at zero bias, demonstrating significant performance advantages. Theoretical analysis further indicates that tuning material layer thickness can excite plasmon resonance effects, thereby enhancing light absorption and optimizing device photoresponse characteristics. This work provides material and structural design references for low-cost, scalable fabrication of low-power self-driven all-fiber detectors, holding positive implications for advancing miniaturization and integration in optical communication and sensing systems.