High-Performance Self-Powered Infrared Photodetector via Semiconducting Graphene Nanoribbon/Germanium Vertical Heterojunctions with Robust Thermal Stability

Self-powered photodetectors stand as a cornerstone for next-generation low-power electronics, with promising applications in optical communications, environmental monitoring, night vision, and beyond. However, achieving high performance in these devices, particularly under elevated temperatures, remains a persistent challenge. Herein, a short-wavelength infrared (SWIR) self-powered photodetector based on semiconducting graphene nanoribbons (GNRs)/germanium (Ge) vertical heterojunction is presented, demonstrating high-performance detection at 1550 nm. Benefiting from the combined effects of the built-in electric field and interfacial photogating, the photodetector achieves a responsivity of 10.21 A/W, a detectivity of 2.36 × 1011 Jones, and an external quantum efficiency (EQE) of 817% in self-powered mode. Under a reverse bias of -3 V, the photodetector delivers a responsivity of 167.3 A/W, a detectivity of 1.45 × 1010 Jones, and an EQE of 104%. Notably, the device retains a measurable photoresponse at temperatures up to 95 °C, with responsivities of 3 A/W at -3 V bias and 0.1 A/W at zero bias. Together with the demonstrated self-powered infrared imaging capability, our results provide a promising strategy for high-performance, thermally robust SWIR photodetection in demanding environments.