Enhancement in Photovoltaic Performance of Dye Sensitized Solar Cells Using Cu and Cu:Ag Co-Doped TiO2 Photoanode

Abstract

Dye Sensitized Solar Cells (DSSCs) are low cost solar cells offering big room for improvements in its photovoltaic performance by maneuvering semiconductor properties, dye adsorption, electrolyte stability etc. For the first time, we have co-doped TiO2 with silver (Ag) and copper (Cu) to enhance both charge collection and light absorption as well as reduce recombinations for DSSCs. For high solar cell efficiency 3wt% Cu and 3wt% Cu:Ag doped TiO2 nps were successfully prepared for Dye Sensitized Solar Cells (DSSCs). Modified photoanode was prepared using surface adsorbed N719 dye on doctor blade coated TiO2, Cu:TiO2 and Cu:Ag:TiO2 thin films. It was observed that optimum doping concentration of Cu and silver was 3wt% each. DSSCs with Cu:Ag:TiO2 thin film showed higher conversion efficiency under full sunlight illumination when compared to DSSCs assembled using Cu:TiO2 and undoped TiO2. The obtained efficiencies for DSSCs with undoped TiO2, Cu:TiO2 and Cu:Ag:TiO2 photoanodes were 2%, 2.7% and 4.5% respectively. Solar cells assembled with Cu only doped TiO2 electrode when compared with cells assembled using pristine TiO2, showed an increase in Voc while Jsc was decreased Furthermore, cells doped with both Ag and Cu showed enhancement in both Voc and Jsc. The enhancement in cell performance has been discussed in context of morphology, crystal phase, presence of bonds etc. in nanoparticles. Considering overall better performance, Cu:Ag doped TiO2 photoanodes can be considered as potential photoanodes in DSSCs.