Characterization of N719 Dye Desorption on TiO<sub>2</sub> Nanotube Arrays Used for Dye-Sensitized Solar Cells

Abstract

In this work, we developed a method to quantitative analyze the absorption and desorption of N719 dye on TiO2 nanotube arrays. TiO2 nanotube arrays were fabricated by anodizing titanium foils in an organic electrolyte using a two-electrode configuration with a platinum mesh as the counter electrode. TiO2 nanotube arrays were then annealed under 450 °Cfor 3 hours and immersed in N719 dye solution for 24 hours. The dye-sensitized TiO2 nanotube arrays were soaked in an electrolyte solution and stored in a dark closed vessel for 76 days. Then they were desorbed by KOH solution (pH=10). According to UV-visible absorption spectra and Lambert-Beer's law, the desorption rate of N719 dye on 9 µm thick TiO2 nanotube arrays was calculated to be 36%. The results provide a valuable reference to study the dye desorption and stability of the dye-sensitized solar cells.