Low-Temperature Fabrication of TiO₂ Necking Electrode by Sol–Gel Method and its Application to Dye-Sensitized Solar Cell

Abstract

The low-temperature fabrication of TiO 2 electrodes for use in a dye-sensitized solar cell was studied. The use of the sol–gel necking method with a Ti–precursor solution added to a paste including TiO 2 nano particles resulted in a high-performance TiO 2 electrode. A solar cell using the electrode showed a high efficiency of almost 2%, even when sintered at 200 °C. The improvement in the efficiency was due to the increase in photocurrent of the cell. Increasing the specific surface area of the TiO 2 electrode sintered at around 200 °C was corresponded to an increase in the number of micropores. However, it did not contribute to the increase in the amount of adsorbed dye nor did it improve photocurrent. Rather, the crystallization of the added Ti–precursor solution and subsequent increase in conductivity of the TiO 2 electrode improved photocurrent. The phase transition temperature of the Ti–precursor solution from amorphous to anatase was detected at 331 °C by differential thermal analysis (DTA) measurement. To fabricate the TiO 2 electrode for use in a high-performance solar cell at lower temperatures, the control of crystallization is required.