Characterisation and application of new carboxylic acid-functionalised ruthenium complexes as dye-sensitisers for solar cells

A series of ruthenium complexes with and without TiO2, anchoring carboxylic acid groups have been synthesised and characterised using nuclear magnetic resonance (NMR), UV-vis and luminescence. These complexes were adsorbed on thin films of the wide band-gap semiconductor anatase and were tested as photosensitisers under standard conditions. I/V characteristics of such devices revealed superior performance of the non-symmetric complexes [4'-(4-bromophenyl)-[2,2'; 6',2"] terpyridine]Ru(II) [4'-(4-bromopheny)-[2,2'; 6',2"] terpyridine-4,4"-dicarboxylic acid] and [2,2'; 6',2"] terpyridine Ru(II) [2,2'; 6',2"] terpyridine-4'-carboxylic acid with a maximum output power similar to 0.016mWcm(-2) under illumination at 100mWcm(-2) AM1.5 and efficiencies 3 times higher than the symmetric complexes. (c) 2006 Elsevier B.V. All rights reserved.