New ruthenium sensitizers containing styryl and antenna fragments

摘要

Amphiphilic ligands 4'-((4-(5-pyridin-4-yloxy)pentyloxy)styryl)-4-methyl-2,2'-bipyridine (L1), 4,4'-bis((E)-4-(5-(pyridin -4-yloxy) pen tyloxy)styryl)-2,2'-bipyridine (L2), 4'-(4-(5-(4'-cyano-4-biphenoxy)pentyloxy)styryl)-4-methyl-2,2'-bipyridine (L3), and 4'-(4-(5-(zinctetrakis-5,10,15-tritolyl-20-(4-hydroxyphenyl)porphyrin)pentyloxy)styryl)-4-methyl-2,2'-bipyridine (L4) and their heteroleptic ruthenium(11) complexes of the types [Ru(Ll)(L)(NCS)(2)] (D20), [Ru(L2)(L)(NCS)21 (D21), [Ru(L3)(L)(NCS)21 (D22), and [Ru(L4)(L) (NCS)(2)] (D23) (where L = 4,4'-bis(carboxylic acid) -2,2'-bipyridine) have been synthesized, as photosensitizers for nanocrystalline dye-sensitized solar cells. All complexes D20-D23 exhibit a broad MLCT band around 520-530 nm in DMF and an emission band around 740-790 nm in DMF. We have studied photovoltaic performances based on the newly synthesized dyes. Under standard AM 1.5 sunlight, the dye D20 gave a short-circuit photocurrent density of 13.31 mA/cm(2), an open-circuit voltage of 0.64 V, and a fill factor of 0.68, corresponding to an overall conversion efficiency of 5.81%. (c) 2007 Elsevier B.V. All rights reserved.