Fabrication of mesoporous TiO₂ electrodes by chemical technique for dye-sensitized solar cells

A new chemical technique for preparing screen-printing paste from commercially-available P-25 powder was proposed to fabricate TiO₂ electrodes for dye-sensitized solar cells (DSSCs). The TiO₂ powder and acetic acid were dispersed in ethanol, following that the reactants solutions kept at 80 °C for 12 h, then dried in oven for 6 h. This process made the TiO₂ particle positively charged and highly dispersed in water. Additionally flocculating reaction using hydrochloric acid was done to change the dispersed TiO₂ colloid into viscous paste, which omitted the process of adding polymers as thickener, and kept the purity and porosity of electrodes. The mesoporous transparent TiO₂ films about 14 μm thickness without cracking and peeling-off were fabricated on conducting glass substrates. A high conversion efficiency of 8.07% was obtained under 100 mW cm^-2 AM 1.5 illumination.