Photovoltaic properties of the natural dyes of chlorophylls consist ofChl a,Chl b,Chl c2,Chl d,Phe a,Phe y,andMg-Phe aand have been studied in the gas phasesand water. The extension of theπ-conjugated system, the substitution of the centralMg2+, and proper functional groups in the chlorophyll structures can amplify thecharge transfer and photovoltaic performance.Chl ashows more favorable dynamicsof charge transfer than the other studied chlorophylls.Chl d,Phe a,Phe y,andMg-Phe ahave a greater rate of exciton dissociation in comparison withChl a,Chl b,andChl c2originating from a lower electronic chemical hardness, a lower exciton bind-ing energy, and a bigger electron-hole radius. As a result, better efficiencies of lightharvesting and energy conversion of the chlorophylls mainly appear in the Soret band.The light-harvesting efficiency values of the chlorophylls in water show that solventfavorably affects the ability of light harvesting of the photosensitizers. Finally, basedon the energy conversion efficiency,Chl a,Phe a,andMg-Phe aare proposed as thebest candidates for use in the dye-sensitized solar cells.

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