Abstract
A brief review on the development of dye-sensitized solar cells (DSSCs) is presented, with the main focus on ruthenium complexes, as photosensitizers of nanocrystalline TiO2 films. In a DSSC, the charge separation is initiated at the adsorbed dye, which is bound at the interface of a TiO2 film. Careful modification of the dyes can tune the spectroscopic, electrochemical properties and photovoltaic performance of the solar cells. It is necessary to optimize the properties of the dye in conjunction with other factors in order to best exploit and be fully compatible with other cell modifications in the development of cheap and efficient photovoltaic systems. In this review, current strategies for the molecular design of the ruthenium complexes including improving the light harvesting in the visible and near-IR region, increasing high optical extinction coefficients and increasing the charge separation and stability of the dyes are discussed.
Keywords: Anchoring ligand, ancillary ligand, charge separation, dye-sensitized solar cells, electrolytes, fill factor, molar extinction coefficients, molecular design, open-circuit photocurrent, overall conversion efficiency, panchromatic sensitization, photovoltaic performances, ruthenium complexes, stability, short photocurrent