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.