Electrospun Fe–Mn/PAN Composite Nanofibers for Enhanced UV Photodetection: Structural and Bandgap Modulation

Electrospun polyacrylonitrile (PAN) nanofibers are robust, flexible, and easy to fabricate; however, their wide optical bandgap makes them undesirable for use in ultraviolet (UV) optoelectronic devices. This study demonstrates the enhancement of PAN nanofibers by incorporating transition-metal oxides, specifically iron and manganese, to alter their electronic structure and improve optoelectronic performance. Electrospun Fe–Mn/PAN composite nanofibers were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible spectroscopy, and current-voltage measurements to examine their morphology. The findings indicate that the addition of iron and manganese markedly diminished the fiber diameter from 245.5 nm to 145.2 nm. It also enhanced crystallinity from 44.4% to 50.7% and lowered the optical bandgap from 4.2 eV to 3.65 eV. Further, these changes introduced defects and electronic states, improving photoconductive response and photocurrent. The modified nanofibers performed optimally in optoelectronics than the unmodified PAN. The results indicate that Fe–Mn/PAN composite nanofibers are promising materials for UV photodetectors and other optoelectronic applications, enabling enhanced functionality and broader adoption.