Dye-sensitized solar cells using nanocrystalline ZnO as the photoanode and a metal-free sensitizer with a benzothiadiazole entity directly connected to the 2-cyanoacrylic acid acceptor exhibited an efficiency (5.18%) higher than those using the TiO(2) photoanode. Use of a hierarchical ZnO back scattering layer further improved the efficiency to 5.82%.