Metal complex sensitizers in dye-sensitized solar cells

A brief review of the investigation of solar energy conversion and the development of dye-sensitized thin-layer solar cells is presented, with the main focus on dyes, specially on d(6) metal complexes employed, since 1998, as photosensitizers of nanocrystalline semiconductors. An extensive literature coverage of the spectroscopic properties and the performance of solar cells employing a series of cis-[Ru(dcbH(2))(2)LL'] species, in which dcbH, is 4,4'-(CO2H)(2)-2,2'-bipyridine and L and/or L' are ancillary ligands, is presented along with non-carboxylic acid anchoring polypyridine-ruthenium complexes. The utilization of other d(6) metal complexes and natural extracts, with emphasis on Brazilian products, is also reviewed. A List of ligands with structures and a series of Tables summarize the collected data. The research and development on dye-sensitized solar cells conducted at our Laboratory of Inorganic Photochemistry and Energy Conversion at the University of Sao Paulo-Brazil is also covered in this context as a part of this special issue in homage to Prof. Gratzel. (C) 2004 Elsevier B.V. All rights reserved.