Natural dye-sensitised solar cells with Titania nanoparticles

Nanophotonics, dealing with behaviour of light at nanoscale is an emerging area which has a lot of potential applications in dye - sensitised solar cells. Dye-sensitised solar cells have aroused much interest in the recent past because of their low cost and simple fabrication procedure which can be optimized to give better light conversion performance. Using nanoparticles as light harvesting agents has the advantages of high surface area to capture light and their wide band gap increases the light conversion efficiency by forming multiple junctions (discrete energy band structure). In this study, a thin layer of titanium dioxide nanoparticles have been used to create the active layer (anode) which is impregnated with dye molecules. Natural dyes were used. Performance variation with different dyes were studied. A spray coated graphite electrode was used as the cathode. TiO₂ nanoparticles were synthesised by sol-gel method. The maximum voltage obtained was about 1 V and the current was about 100 mico-amperes, which is a very significant result for a dssc with an active area of 0.20 cm².