Inkjet-printing of tio₂ co-solvent ink: from uniform ink-droplet to tio₂ photoelectrode for dye-sensitized solar cells

We have investigated the inkjet-printing of Tio₂ films for the fabrication of dye-sensitized solar cells (DSSCs). In order to realize the uniform printing of Tio₂ films, the co-solvent ink was designed by introducing a drying agent to the ink. This co-solvent ink induces a circulating flow within ink droplets and leads to the uniform lines and films by inkjet. A theoretical model was used to predict the optimal ink-droplet pitches for the inkjet-printing of uniform lines. This model also contributes to the formation of uniform films since they are filled with the inkjet-printed lines. The inkjet-printed Tio₂ films were used as photoelectrodes for dye-sensitized solar cells. The thickness of the inkjet-printed Tio₂ films was varied to optimize the photovoltaic performance of DSSCs. Since no organic additives were introduced into the Tio₂ inks, the feasibility of reducing the annealing temperature for Tio₂ photoelectrodes was investigated. This study may suggest an opportunity to fabricate DSSCs at low temperature