Poly(phenylene cyanovinylenes) carbazole based conjugated polymer as a photosensitizer for dye-sensitized solar cells

A carbazole based new n-type conjugated polymer (CP) has been synthesized and employed as a photosensitizer in polymer-sensitized solar cells (PSSCs). The synthesis of CP was accomplished by the reaction of appropriate monomer dialdehyde with aromatic dinitriles, under Knoevenagel condensation conditions followed by its characterization by 1H NMR and FT-IR. The band gap of CP measured by cyclic voltammetry (CV), density functional theory (DFT) and diffuse reflectance (DR) UV-vis spectroscopy revealed closely matched values of 2.57, 2.47, and 2.64 eV respectively. Under the illumination of AM1.5G (100 mW cm−2), CP based PSSCs exhibited power conversion efficiency of 2.08% with a short-circuit current density (JSC) of 7.0 mA/cm2, an open-circuit voltage (Voc) of 534 mV and a fill factor (FF) of 55.85%.