الفهرس 
acknowledgmentOnly 14 pages are availabe for public view
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Abstract
In this work doped PANI films have been prepared electrochemically as counter electrodes for the dye sensitized solar cells. Doping of PANI during polymerization is carried out in order to enhance its electrocatalytic activity toward I3- reduction. The doping has been performed by adding inorganic acids and neutral salts. The effects of dopant concentration and type and polymerization potential range have been investigated. The optimum concentration of HCl and HNO3 as dopants is 1.1M as indicated by the performance of the dye sensitized solar cells fabricated with this optimum concentration.
Films doped with HNO3 show higher electrocatalytic activity compared with those doped with HCl, HClO4 and H2SO4. This because HNO3 has a sponge-like morphology, low solubility and optimum electronegativity. The proper polymerization potential range is from -0.2V to 0.9V. This range allows the polymerization of aniline without any degradation peaks. The addition of a neutral salt during the electrochemical polymerization enhances the electrocatalytic activity of prepared PANI. Adding NaCl during polymerization, enhances the photovoltaic output parameters of the prepared cells more than KCl due to the high electron affinity of Na+ compared with K+. The presence of NaCl during the preparation of doped PANI-HNO3, allows a reduction of both the required doping concentration and the potential range of polymerization. This in turn decreases the PANI degradation and the cross-linking. Increasing the concentration of NaCl enhances the electrocatalytic activity of the films and consequently the efficiency of the prepared cells. Beyond a concentration of 2M NaCl, the efficiency is decreased gradually. The prepared Doped PANI films have been used for fabricating dye sensitized solar cells and the highest obtained efficiency is found to be 1.73%.