Achieving high-performance flexible UV photodetectors: modulating oxygen vacancies via hydroxymethylated PEDOT and surface functionalities of N-doped graphene quantum dots

This study presents a flexible UV photodetector with an organic-inorganic hybrid structure, fabricated using advanced face-to-face self-assembly. The detector is composed of PEDOT-CH 2 OH and nitrogen-doped graphene quantum dots (N-GQDs) modified zinc oxide nanoflowers (ZnO NFs). The sulfur and hydroxyl groups in PEDOT-CH 2 OH, along with nitrogen and oxygen functional groups in N-GQDs, promote the formation and stabilization of oxygen vacancies (Vo) on the ZnO NFs surface. This significantly enhances carrier separation efficiency, reduces electron-hole recombination, and improves the detector's performance. Under 365 nm UV light, the device achieves a response rate of 1.31 mA W −1 at 0V bias, with fast rise times (0.078 s) and fall time (0.093 s). The detector shows excellent stability and rapid photonic response, providing solid support for wearable electronics and new theoretical guidance for ZnO photodetector improvements.