D-p-A ORGANIC DYES FOR TRANSPARENT DYE-SENSITIZED SOLAR CELLS

Since their discovery in 1991,[1] Dye-Sensitized Solar Cells (DSSC) have been considered a very promising technology to convert solar energy in electric current because of their low cost of production and their easy integration in buildings and objects.[2] The photoactive material inside a DSSC is the dye.[3] Totally organic dyes have recently found great interest in this field, thus we decided to study the synthesis of new organic D-p-A dyes with broad light absorption and high extinction molar coefficients: molecules with these features were expected to give good photovoltaic performances within thin-layer, transparent DSSCs. With this aim and aided by theoretical calculations, we designed a class of thiazolo[5,4-d]thiazole-based dyes (TTZ3-7) having different donor and acceptor groups.[4] The dyes were synthesized and subjected to a complete spectroscopic and electrochemical characterization. Thin-layer transparent test DSSCs were built with our dyes, achieving power conversion efficiencies up to 7.71%. References: 1. O'Reagan, B.; Grätzel, M. Nature 1991, 353, 737-740. 2. Dye-sensitized solar cells (Ed.: K. Kalyanasundaram), EPFL Press, Lausanne 2010. 3. Hagfeldt, A.; Boschloo, G.; Sun. L.; Kloo, L.; Petterson, H. Chem. Rev. 2010, 110, 6595-6663. 4. Dessì, A.; Calamante, M.; Mordini, A.; Peruzzini, M.; Sinicropi, A., Basosi, R.; Fabrizi de Biani, F.; Taddei, M.; Colonna, D.; Di Carlo, A.; Reginato, G.; Zani, L. Chem. Commun. 2014, 50, 13952-13955.