Conducting polymer blends (polyaniline/polypyrrole) as counter electrode materials in dye sensitized solar cells

Dye sensitized solar cells have attracted lot of research interest in recent years due to their low production cost, higher transparency, easy fabrication and tunable optical properties. Generally, Platinum is used as the catalytic active counter electrode material in the cell which has achieved about 14.1% efficiency. Platinum is an expensive and rare metal and is susceptible to corrosion in long term applications. Therefore lot of research interest is focused on finding low cost, earth abundant alternatives as the counter electrode materials. Due to the low cost, higher conductivity, higher stability, easy preparation and easy fabrication, conducting polymers have become an advanced alternative. Generally, product performance of polymers has improved by blending two or more polymers. Conductivity, stability, structures and performances of pure polyaniline and pure polypyrrole are highly investigated. Among all counter electrode fabricated with conducting polymers, polyaniline has shown the highest power conversion efficiency in dye sensitized solar cells. Performance changes of dye sensitized solar cells have been discussed here by fabricating the counter electrode with polymer blends with different mass ratios of polyaniline and polypyyrole. Out of all the blends tested, polymer blend with 1:1 mass ratio of polyaniline:polypyrrole showed the lowest charge transfer resistance and highest efficiency in Dye-Sensitized Solar Cells.