Mesoscopic Dye‐Sensitized Solar Cells

Meso-Substituted Porphyrins for Dye-Sensitized Solar Cells

“…YD26 combining all the favorable structural components (naphthalene spacer, alkoxy wrapped structure, and carboxyl binding group) logically achieved the best PCE of the series (η = 8.04%). Although cyano- and (cyano)­phenyl- acrylic acid groups have been widely used as efficient anchors for a great variety of organic dyes, − including porphyrins (vide infra, see discussion on section ) this conceptual design in the light of these results, seems, however, not working well when transposed to “push–pull” porphyrins anchored through ethynylphenyl cyanoacrylic acid, which underperform clearly their ethynylcarboxyphenyl analogues.…”

“…A schematic representation and processes occurring in a conventional n-type, TiO 2 dye-sensitized solar cell (DSSC) − are depicted in Figures , , and . There are four main processes that occur in a DSSC: (I) absorption of the light by a sensitizer, leading to the electronic excitation of the sensitizer to an excited state (Dye*) (i.e., HOMO → LUMO transition), (II) the generated exiton dissociates (charge separation process) to inject an electron into the metal oxide (typically TiO 2 nanoparticles − conduction band (CB) , from the excited state of the dye (charge transfer process), , (III) the resulting oxidized dye (Dye + ) is restored to the fundamental state (Dye) by a reducing agent present in the electrolyte (typically I – ions), (IV) the photogenerated electrons at the anode flow through an external circuit to reach the Pt counter electrode (cathode), where the oxidized redox mediator is regenerated (e.g., I 3 – + 2e – → 3I – ).…”