Modification of TiO2 Surface by Disilanylene Polymers and Application to Dye-Sensitized Solar Cells

The surface modification of inorganic materials with organic units is an important process in device preparation. For the modification of TiO2, organocarboxylic acids (RCO2H) are usually used. Carboxylic acids form ester linkages (RCO2Ti) with hydroxyl groups on the TiO2 surface to attach the organic groups on the surface. However, the esterification liberates water as a byproduct, which may contaminate the surface by affecting TiO2 electronic states. In addition, the ester linkages are usually unstable towards hydrolysis, which causes dye detachment and shortens device lifetime. In this review, we summarize our recent studies of the use of polymers composed of disilanylene and π-conjugated units as new modifiers of the TiO2 surface. The TiO2 electrodes modified by those polymers were applied to dye-sensitized solar cells