10% Efficiency dye-sensitized solar cells using P25 TiO₂ nanocrystalline electrode prepared by a bead-milling method

Dispersions of TiO₂ nanoparticles were prepared from titania powder (P25, Degussa) using a bead-mill method. The dispersion was controlled by the mixing time and was observed using dynamic laser-light scattering. TiO ₂ screenprinting pastes were prepared from the TiO2 dispersions for application as photoelectrodes in dye-sensitized solar cells (DSSCs). The coated nanocrystalline TiO₂ electrodes were evaluated using X-ray diffraction (XRD) and a haze meter. The shape and crystallinity of the TiO ₂ nanoparticles were not changed, but the transparency was improved by the beadmilling process. However, aluminum contamination on the TiO2 surface was found to increase with bead-milling time. A TiO₂ paste prepared from an optimized dispersion was used to fabricate a DSSC with 10% photoenergy-conversion efficiency.