Combination of Cobalt and Iron Polypyridine Complexes for Improving the Charge Separation and Collection in Ru(terpyridine)₂‐Sensitised Solar Cells

Abstract

Mixtures of polypyridine Fe(II) and Co(II) complexes are used as electron mediators in Ru-thienyltpy-sensitised solar cells (tpy=terpyridine). The use of the metalorganic redox couples allows for improved charge-collection efficiency with respect to the classical iodide/iodine couple which, when associated to Ru-tpy(2) dyes, usually produces poor performance. The improved charge collection is explained by a combination of effective dye regeneration and decreased recombination with the oxidised electrolyte on the basis of data obtained by transient spectroscopy and photoelectrochemical measurements. The efficiency of the regeneration cascade is also critically dependent upon the ability of the Co(II) complex to intercept Fe(III) centres, as clearly indicated by chronocoulometry experiments.

Terpyridine and Quaterpyridine Complexes as Sensitizers for Photovoltaic Applications

“…Tpy-bearing polyphenylene-vinylene and thienyl-fluorene units were exploited in order to incorporate the resulting Ru complexes in the polymer chains; carboxyl acid functionalization of the bipyridine moieties resulted in improved efficiency. Caramori et al [115], using an heteroleptic thienylterpyridine Ru complex, improved the electron collection efficiency owing to an electrolyte based on the combination of cobalt and iron polypyridine complexes.…”

Syntheses and applications of furanyl-functionalised 2,2’:6’,2’’-terpyridines

“…It is interesting to note that this procedure can be applied to the free ligand, but also directly on bis(terpyridine) Ru(II) complexes without degradation of the chelate cycles [43–47] (Scheme 9, Table 2). A series of carboxylic acid-functionalised complexes 44 – 48 was thus obtained from furanyl-functionalised complexes 39 – 43 using this methodology.…”

Tuning electronic structures of uranyl fluorides via increasing equatorial pyridyl number and extending pyridyl conjugation

“…[1][2][3][4] Many of their transition metal complexes have been found to show peculiar optical, electrochemical and magnetic properties. [4] Polypyridyl ruthenium(II) complexes, for instance, have achieved great success as photosensitizers in dye-sensitized solar cells (DSSCs), because exhibiting intense and broad metal-to-ligand charge transfer (MLCT) absorption bands in the visible-light area.…”