Controlled Synthesis of Nanostructured ZnO Films for Use in Dye-Sensitized Solar Cells

Nanostructured ZnO films were fabricated by a chemical bath deposition method through an initial precipitation of layered hydroxide zinc acetate (LHZA) and subsequent pyrolytical transformation to ZnO. Contrary to our previous reports on the formation of flowerlike LHZA films at 60 degrees C, we found that a morphology like brussels sprouts was obtained at a room temperature deposition of LHZA by controlling the reaction conditions carefully. The discrepancy in the formation mechanisms was discussed based on the supersaturation, nucleation, and crystal growth of LHZA in a methanolic solution of zinc acetate dihydrate. The resultant ZnO films were applied to photoanodes of dye-sensitized solar cells with N-719. An overall light-to-electricity conversion efficiency reached 5.1% at air mass 1.5 (100 mW/cm(2)) when using the sproutslike ZnO film approximately 15 mu m in thickness. (c) 2010 The Electrochemical Society.