A viscous titania paste with a single coating-sintering step for 8–24 μm thick, high-haze, high-quality TiO2 films of dye-sensitized solar cells

• We prepare 8–24 μm thick P25 films.
• P25 films were prepared by coating one time.
• P25 films were prepared by sintering one time.
• The low-price of the paste has promising applications for industrial production.
• P25 films have high light scattering ability and high-quality without cracking and delamination.

A viscous TiO2 paste was prepared by ball-milling commercially available P25 with ethylene glycol and citric acid. The conventional three- or four-fold deposition process was replaced by a single coating-sintering step of TiO2 compound. That is coating the paste on Fluorine-doped SnO2 conductive glass, followed by sintering at high temperature. TiO2 films varying from 8 μm to 24 μm could be fabricated by this single coating-sintering step. The high viscosity of the paste, the esterification between ethylene glycol and citric acid and the subsequently polyester decomposition in the sintering process were the reasons to make high-quality thick film without cracking and delamination. 7.36% photoelectrical-conversion efficiency was achieved by using the photoelectrode with its P25 film thickness of 14.3 μm. Therefore, the paste would have promising applications for industrial production because of its low-price and simple process.