IR Study on N719 Dye Adsorption with High Temperature Dye Solution for Highly Efficient Dye-Sensitized Solar Cells

N719 dye adsorption by immersing TiO 2 electrodes in a high temperature N719 solution for dye-sensitized solar cells (DSCs) was investigated by IR absorption spectroscopy using a multiple internal reflection geometry. In this study, an N719 dye solution of a mixture of 10 mL acetonitorile and 10 mL tertiary-butyl alcohol containing N719 at a concentration of 0.36 mg/mL was examined. When the solution temperature for dye adsorption was increased from 20 to 80°C, the N719 dye chemisorbed on TiO 2 with the bidentate bond was increased and this high temperature dye adsorption was effective in promoting power generation in the DSCs. Decreasing the solution temperature from room temperature to 0°C resulted in an increase in the physisorbed dye on the TiO 2 surface, which may rather deteriorate power generation. The IR absorption spectroscopy indicates the presence of an activation barrier for N719 to chemisorb on the TiO 2 surface. A dye adsorption method using a high temperature dye solution for higher power generation efficiency is discussed in this paper.