Polyaniline-titania solid electrolyte for new generation photovoltaic single-layer devices

摘要

In this study, in situ chemical oxidative polymerization of very low quantities of aniline doped with HC1 using ammonium persulfate inside an aqueous solution of 10 wt.% of titanium dioxide was used to prepare a novel photovoltaic paint. Photoelectrical properties of the composite have been observed and the operating principle of the photovoltaic device is presented. We report an enhancement of the absorption of TiO_2 powder in the visible range due to the sensitization by conductive polyaniline. Under illumination an open circuit voltage of 593 mV and a short circuit current density of 0.502 A m~(-2) were recorded. The surface conductivity of PANI-TiO_2 pellets is measured using the four-point probe technique. The percolation theory together with variable range hopping explained the behavior of the surface conductivity of the composites. Morphological analysis using Transmission Electron Microscope showed the core/shell structure of the composites and energy dispersive X-ray showed the homogeneity of the composite. Fourier transform infrared spectroscopy confirmed the chemical adsorption of polyaniline at the surface of TiO_2. UV-visible spectroscopy showed a shift of the polaron energy inside the polyaniline energy gap. The proposed morphology is showed to be responsible for the photoactivity of the composite.