The synergistic effect of two photosynthetic pigments in dye-sensitized mesoporous TiO₂ solar cells

Chlorophyll and xanthophyll were extracted from different plants for use as sensitizer colorants; cells were sensitized using chlorophyll, xanthophyll and a mixture of the two pigments. It was found that energy conversion efficiency (η) and maximum output power (P_max) were 15.16% and 8.31% higher than that achieved by the linear superposition of the cells sensitized by individual pigments. This indicates that the mixed pigment co-sensitization entails a synergistic effect in the energy transfer of the pigment-sensitized mesoporous TiO₂ solar cells. Fluorescence analysis revealed that the electron transfer between chlorophyll and xanthophyll in the mixed pigment co-sensitized mesoporous TiO₂ solar cells was similar to that in 'zigzag chains' of photosynthesis.