Four organic dyes (XS10-13) employing carbazole unit as electron donor and N,N-dimethylarylamine moieties as electron-donating groups were designed and synthesized for nanocrystalline TiO(2) dye-sensitized solar cells. The electron-donating groups of dimethylarylamine increase the electron density of donor moiety and enhance the molar extinction coefficient of dyes. For a typical device the maximum IPCE value could reach 86%, with a short-circuit photocurrent density (J(sc)) of 9.8 mA cm(-2), an open-circuit photovoltage (V(oc)) of 642 mV, and fill factor (FF) of 0.63, which corresponds to an overall conversion efficiency (eta) of 4.0%. For a comparison, the N719-sensitized TiO(2) solar cell showed an efficiency of 6.4%. (C) 2011 Elsevier Ltd. All rights reserved.