Synthesis, Characterization, and Application of Metal-Free Porphyrin Dyes with Different Donors for Dye-Sensitized Solar Cells

Two novel metal-free porphyrin dyes with different donors have been designed and investigated as photosensitizers to improve the light-harvesting abilities of dye-sensitized solar cells (DSSCs). Among the numerous sensitizers, porphyrin dyes absorb strongly in the visible region of the solar spectrum due to changes in their core and facile modification of their electronic properties by structural variations. The two new porphyrin dye molecules contain different functional groups, 2-ethylhexyl, and triphenylamine, as electron donors for the porphyrin structure. The absorbance and electrochemical properties of both the dyes have been investigated. The solar conversion efficiency of the dye-sensitized solar cell using the stronger donor triphenylamine is better than that of the DSSC containing the donor 2-ethylhexyl, with I-/I-3(-) as the redox couple under standard global AM 1.5 solar irradiation.