Investigating the structural and dielectric properties of electrospun nanofibers based on P(VDF-TrFE)/conjugated polymer for optoelectronic applications

Abstract This study investigates the fabrication of semiconductive nanofiber films created from polyvinylidene fluoride-trifluoro ethylene (P(VDF-TrFE)) and Poly [N-9′-heptadecany l-2, 7-carbazole-alt-5, 5- (4′, 7′-di-2-thieny l-2′, 1′, 3′-benzothiadiazole)] (PCDTBT) using the electrospinning technique. Scanning electron microscopy (SEM) revealed that films ranging from 200 to 400 nm in diameter exhibit a smooth fiber topology. Attenuated total reflectance for Fourier transform infrared (ATR-FTIR) spectra showed symmetric, antisymmetric, and non-significant chemical interactions. X-ray diffraction (XRD) analysis revealed a ferroelectric β phase and amorphous structure, with no distinct Bragg diffraction peak. The UV-Vis spectra indicated the presence of semicrystalline P(VDF-TrFE) in the electrospun nanofiber film, where the carbazole units and conjugated main chains resulted in PCDTBT absorption at 415 nm and 589 nm. Blending PCDTBT with P(VDF-TrFE) lowered the band gap and enhanced Urbach energy (EU). Incorporating PCDTBT with P(VDF-TrFE) improved the DC conductivity from 1.42×10-4 S cm-1 to 1.07×10-3 S cm-1. Polarization at the semiconductor-insulator interface improved the nanofiber blend's characteristics, including a lower bulk resistance (Rb) and a greater dielectric constant than P(VDF-TrFE). These Nanofibers may be employed in transparent electrodes and coatings for optoelectronic devices that need visible spectrum transparency and UV protection.