Synthesis of Zinc Porphyrin Sensitizers for Dye-Sensitized Solar Cells by Tuning Electron-Donor Group

Dye-sensitized solar cells (DSSCs) are considered a promising solution to current energy challenges. In this study, three porphyrin sensitizers ZnP1–ZnP3 with donor-π-acceptor (D-π-A) configurations were synthesized. The donors included 9,9-dimethylfluorene, 4-biphenyl, and 1,1′:3′,1″-terphenyl groups, whereas alkynylbenzoic acid was used as the acceptor. The modification of the side alkyl chain addressed the poor solubility of the porphyrin sensitizer. The synthesized porphyrin sensitizers were structurally characterized by nuclear magnetic resonance, high-resolution mass spectrometry, and ultraviolet absorption spectroscopy. The introduction of electron donor groups into 1,1′:3′,1″-terphenyl and alkynylbenzoic acid into the acceptor group improved the light-harvesting ability of the sensitizer, increased the short-circuit photocurrent density, and enhanced cell efficiency ( η = 3.6%). Finally, density functional theory was used to verify the experimental results.