Synthesis, Characterization, and Photovoltaic Properties of Poly(3-Phenyl Azomethine Alkylthiophene) Polymers

Poly(3-phenyl azomethine ethylthiophene) (PPAET) and poly(3-phenyl azomethine butylthiophene) (PPABT) have been synthesized by the oxidative coupling method using FeCl3 as the oxidant. The polymers were thoroughly characterized using Fourier-transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis. The concomitant thermal, optical, and electrochemical properties of the polymers revealed that they possess excellent potential as photovoltaic materials. The electrochemical bandgaps of PPAET and PPABT are calculated to be 2.19 eV and 2.14 eV, respectively. The absorption spectra showed broad absorption over the wavelength range of 350 nm to 590 nm with a maximum absorption peak at 407 nm and 415 nm (λmax), respectively, for PPAET and PPABT. Polymer photovoltaic cells based on blends of polymers and TiO2 nanoparticles have been fabricated, and the power conversion efficiencies (PCE) of the photovoltaic cells were measured to be 0.102% and 0.125%, respectively, for PPAET and PPABT.