Triaryl linked donor acceptor dyads for high-performance dye-sensitized solar cells

The effect of changing substituents of organic dyes for their performance on dye-sensitized solar cells (DSSCs) is examined These dyes consist of all aromatic amine donor group, a cyanoacrylic acid acceptor croup. and a triaryl spacer group, While they are linked together by consecutive palladium catalyzed coupling reactions. These materials exhibit strong charge transfer absorption bands in the UV/vis region Their redox potential levels were estimated by cyclic voltammetry, and found to suit well to the charge flow in DSSCs. Adding electron-donating substituents oil the phenyl groups of aromatic amines increased the electron density on the donor groups, therefore reduced the HOMO/LUMO band gap. These dyes were chemisorbed on the surface of nanocrystalline TiO2, and fabricated into DSSCs through standard operations. For a typical device the maximal monochromatic incident photon-to-current conversion efficiency (IPCE) call reach to 80%, with a short-circuit photocurrent density (J(sc)) 16.34 mA cm 2, all open-curcuit photovoltage (V-oc) 0.68 V. and fill factor (FF) 0.55, which corresponds to an overall conversion efficiency of 6 05%. (C) 2009 Elsevier Ltd. All lights reserved