Drip and evaporation method for dye-TiO2 nano junction formation in dye sensitized solar cells

The dripping of dye solution and solvent evaporation method for faster dye adsorption in dye-sensitized solar cells (DSCs) was developed and its effect on the adsorption time and the cell performance was studied. N719 dye solution was dripped on to the TiO2 porous layer on the FTO glass substrate with heating. The solvent and water generated from the adsorption reaction quickly evaporated and the dye adsorption rate on the TiO2 porous layer was substantially enhanced so that the dye adsorption time was significantly shortened, from 24 h for the conventional dipping method to 4 min. With the dripping and evaporation method, the DSC efficiency was slightly higher than the dipping method due to the higher dye adsorption. Electron transport properties and characteristics of the DSCs prepared with the dripping and evaporation method and the dipping method were investigated with electrochemical impedance spectroscopy (EIS) measurements.