Effect of orientation and density of hydroxide precursor films on performance of dye-sensitized ZnO solar cells

Layered hydroxide zinc carbonate (LHZC) films were fabricated on glass substrates through a chemical bath deposition method using aqueous solutions. The films had morphologies where sheet-like LHZA particles were accumulated more or less vertically to the substrate surface. Changes in the concentration of a zinc source and the increasing rate of pH had a remarkable effect on the b-axis orientation and the film density of the LHZC films. The morphologies of the LHZC films were maintained after their conversion to ZnO by thermal treatments. The increase in the film density resulted in the improvement of the open-circuit voltage and the fill factor of dye-sensitized solar cells using N719-loaded ZnO films as photoanodes. The light-to-electricity conversion efficiency of 3.49% was obtained in the DSSC using the present ZnO film.