Silver Nanowire-Modified GaN/PEDOT:PSS Hybrid Heterojunctions for Advanced Self-Powered UV Photodetection

Self-powered ultraviolet photodetectors (UVPDs) based on low-cost and high-efficiency hybrid heterojunctions hold great potential for next-generation optoelectronics because their strong built-in electric fields enable rapid carrier separation without external bias. However, simultaneously achieving high responsivity and fast response remains a persistent challenge. In this work, a high-performance self-powered UVPD is realized by introducing silver nanowires (AgNWs) into the PEDOT:PSS layer to form a GaN/PEDOT:PSS-Ag nanowires (AgNWs) hybrid heterojunction. Compared with the pristine GaN/PEDOT:PSS device, the AgNWs-modified PD exhibits a 40% enhancement in self-powered photodetection performance. Under 365-nm illumination, the device delivers a great responsivity of 1.4 A/W, a superior detectivity of $1\times 10^{{13}}$ Jones, and a notable external quantum efficiency as high as 476%. The response speed is also markedly boosted, with the rise and decay times shortened to 52.9 and 84.3 ms, representing reductions of 59% and 73%, respectively. Detailed analysis reveals that the incorporated AgNWs increase the electrical conductivity of the PEDOT:PSS layer and construct highly efficient carrier-transport channels that accelerate carrier transfer, thereby promoting multiple exciton generation (MEG) effect. These findings provide a feasible strategy for improving the self-powered photodetection performance of organic–inorganic hybrid heterojunction UVPDs.