Flexible ultraviolet (UV) photodetectors are essential for next-generation wearable, portable, and large-area optoelectronics; however, their practical implementation is often limited by poor mechanical compliance, slow photoresponse, and inefficient photocarrier transport. Herein, we report a scalable and substrate-compatible strategy for fabricating high-performance flexible UV photodetectors by employing electrospun polyacrylonitrile (PAN) nanofibers as a compliant scaffold and engineered zinc oxide (ZnO) seed layer for the controlled growth of vertically aligned ZnO nanorods (NRs). Systematic optimization of electrospinning and precursor parameters enables the formation of highly stoichiometric ZnO seed layers, which govern NR nucleation, promote vertical alignment, and enhance crystallinity during subsequent hydrothermal growth. The resulting PAN-supported ZnO NRs exhibit improved structural integrity, strong interfacial adhesion, and efficient charge transport. Importantly, the PAN/ZnO heterointerface induces an interfacial electric field that accelerates photocarrier separation and suppresses sluggish surface-trap-mediated kinetics, enabling rapid photoresponse. The flexible PAN/ZnO UV photodetector delivers a high responsivity of up to 30 mA W–1, a specific detectivity of 4.9 × 1011 Jones, and ultrafast rise/fall times of 12/14 s. These performance metrics are retained under repeated mechanical deformation, demonstrating excellent mechanical robustness and electrical stability.
Sharma et al. (Fri,) studied this question.