Effect of TiO 2 Thin Film Morphology on Polyaniline/TiO 2 Solar Cell Efficiency

Abstract

Nanocrystalline titanium dioxide (TiO 2) thin films were prepared by using sol-gel through spin-coating method. An assembly of indium tin oxide (ITO)/TiO 2 /polyaniline (PANI)/Ag was made in a sandwich panel structure. The obtained junction shows rectifying behavior. Additionally, the I/V characteristic indicates that a P-N junction at nanocrystalline PANI/TiO 2 interface has been created. In this experimental study, we depended only on the ratio between titanium and PANI in the process of preparing sol-gel (PANi/TiO 2 at 20% wt). The largest open circuit voltage of 656 mV and short current density of 0.00315 mΑ/cm 2 produce 0.0004% power conversion solar cell (η) under simulated solar radiation (50 mW/cm 2). The thin films of PANI and titanium oxide (TiO 2)/ PANI composites were synthesized by sol-gel technique. Pure TiO 2 powder with nanoparticle size of less than 25 nm and PANI were synthesized through chemical oxidative polymerization of ani-line monomers. The composite films were characterized by high resolution X-ray diffraction, Fourier transform infrared spectroscopy, field effect scanning electron microscopy, and UV-vis spectroscopy. The results were compared with the corresponding data on pure PANI films. The intensity of diffraction peaks for PANI/TiO 2 composites is lower than that for TiO 2 . The characte-ristic of the FTIR peaks of pure PANI shifts to a higher wave number in TiO 2 /PANI composite, which is attributed to the interaction of TiO 2 nanoparticles with PANI molecular chains.