Equivalent circuit analysis of dye-sensitized solar cell by using one-diode model:: Effect of carboxylic acid treatment of TiO2 electrode

For the improvement of dye-sensitized solar cell performance, it is important to analyze the electric mechanism of cells and to employ an effective treatment. Equivalent circuit analysis using a one-diode model was carried out for a dye-sensitized solar cell consisting of a TiO2 electrode treated with carboxylic acid. Carboxylic acid treatment, especially using acetic acid, was effective in increasing the short-circuit current (I-sc) of the cell. As a result of the equivalent circuit analysis, the shunt resistance (R-sh) value tended to increase due to carboxylic acid treatment. In contrast, the series resistance (R-s) value of the treated cell was smaller than that of the nontreated cell. Carboxylic acid treatment was effective not only in improving the electrical contact between TiO2 particles but also in blocking the leakage current from the TiO2 surface to electrolyte. Thus, this analytical method using a one-diode equivalent circuit is useful for evaluating the effect of dye-sensitized solar cell treatment.