Multi-alkylthienyl appended porphyrins for efficient dye-sensitized solar cells

Four porphyrin dyes, incorporating multi-alkylthienyl appended porphyrins as the electron donor, the 2-cyanoacrylic acid as the electron acceptor, and different π-conjugated spacer, have been synthesized for dye-sensitized solar cells (DSSCs). All the porphyrin dyes studied in this work exhibit red-shifted and broadened electronic spectra respect to the reference PZn as expected. By the introduction of thienyl groups at the meso-positions, the energy level of Eox (excited-state oxidation potentials) is significantly shifted to the positive compared with the reference PZn, indicating a decreased HOMO–LUMO gap. The highest power conversion efficiency of the four dyes based on DSSCs reached 5.71% under AM 1.5 G irradiation.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The multi-alkylthienyl appended porphyrin dyes were synthesized and applied in DSSCs. ► All the porphyrin dyes exhibit red-shifted and broadened electronic spectra. ► The HOMO–LUMO energy gaps were decreased by the introduction of thienyl groups. ► The highest power conversion efficiency of the porphyrin dye reached 5.71%.