Mechanochemical synthesis and characterization of poly[(aniline-co-N-(4-sulfophenyl) aniline] nanofibers and its nanocomposite with titanium dioxide nanoparticles and study of their efficiency in hybrid solar cell

The advantages of polyaniline for application in new generation solar cells include its cost-effectiveness, environmentally friendly synthesis, remarkable stability, and the ability to modify the bandgap through the synthesis of its nanocomposites. But a challenge for its nanostructures is the limited solubility in non-toxic solvents, including water, which limits their processability in coating techniques. We overcame this challenge by synthesizing its copolymer with diphenylamine-4-sulfonate and its nanocomposite with titanium dioxide nanoparticles (TiO₂NPs). So through a solid-state and template-free technique and using sodium diphenylamine-4-sulfonate, aniline hydrochloride salt, TiO₂NPs, and FeCl₃∙6 H₂O as an oxidant, poly(N-(sulfophenyl)aniline) nanoflowers (PSANFLs), poly [(aniline-co-N-(4-sulfophenyl) aniline] nanofibers (PAPSANFs), poly(N-(sulfophenyl)aniline) nanofibers/titanium dioxide nanoparticles (PSANFs/TiO₂NPs), and poly (aniline-co-N-(4-sulfophenyl)aniline nanofibers/titanium dioxide nanoparticles (PAPSANFs/TiO₂NPs) were synthesized. Characterization of the synthesized samples was carried out through field emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectra, ultraviolet-visible spectra (UV-Vis), cyclic voltammetry (CV), and elemental analysis (CHNS). The FE-SEM images clearly illustrate that the synthesized samples are of nanoscale dimensions. The band gap values of 2.23 eV for PSANFs/TiO₂NPs and 1.96 eV for PAPSANFs/TiO₂NPs nanocomposites were determined through electrochemical calculations based on cyclic voltammetry curves, showcasing the complementary properties of n and p semiconductors. Using doctor blade method to prepare films from synthesized materials and the architectural pattern of ITO│TiO₂NPs│semiconductor sample│Al, all hybrid solar cells are fabricated. The I-V characteristics and power conversion efficiency (PCE) of the samples were examined and discussed. The PCE values for the four samples were found to be in the range of 0.20–0.82 %.