Sevenfold enhancement on porphyrin dye efficiency by coordination of ruthenium polypyridine complexes

Abstract

Sevenfold enhancement of photoconversion efficiency was achieved by incorporation of peripheral ruthenium complexes to a porphyrin dye, generating supramolecular effects capable of playing several key roles (e.g., transferring energy to, inhibiting aggregation, and accepting the hole generated in the porphyrin center after electron injection), providing new insights for the design of better DSSC photosensitizers.

Porphyrins as Active Components for Electrochemical and Photoelectrochemical Devices

“…202 A supramolecular system has been studied in which the zinc 5-(4-carboxyphenyl)-10,15,20,-tri(4-pyridyl)porphyrin is covalently linked to TiO 2 and three [Ru(dmbpy) 2 Cl] + groups were introduced, upon complexation through the pyridyl substituent. 254 Even though ruthenium complexes are used, the cell efficiency remained quite low (η = 1.2%). However, their introduction caused a seven fold enhancement of the cell efficiency with respect to the corresponding free base and zinc porphyrins, due to several effects such as the inhibition of porphyrin aggregation and their ability to accept the hole and energy transfer from Ru complexes to the porphyrin core.…”

Understanding the Electronic Structures and Absorption Properties of Porphyrin Sensitizers YD2 and YD2-o-C8 for Dye-Sensitized Solar Cells

“…were developed because of their high molar absorption coefficient, relatively simple synthetic procedure, easily modified structures and lower cost. Among them, porphyrins are viewed as one of the more promising dye sensitizers for DSSCs because porphyrin derivatives have better photosynthesis performance, strong UV-visible light absorption, and allow for easy modification/design of their structures [ 41 , 42 ].…”

Strategic Synthetic Approaches to Porphyrin-Based Artificial Light-Harvesting Systems for Solar Energy Utilization

“…Supramolecular porphyrin dye 178 encompassing a meso-4-carboxyphenyl binding site as well as three [Ru(dmbpy) 2 Cl] + complexes (dmbpy = 4,4′-dimethyl-2,2′-bipyridine) coordinated to the meso-(4-pyridyl) positions was synthesized (Chart 55). 190 The coordination of Ru-complexes to the peripheral pyridyl N-atoms of the free base porphyrin or the zinc porphyrin, slightly perturbed the porphyrin energy levels. New absorption bands, characteristic of the ruthenium complexes, were introduced at 294 nm and 505 nm respectively, and were assigned to dmbpy pp-pπ* and Ru II (dπ)-dmbpy(pπ*) charge-transfer transitions.…”