Silatrane as a new versatile alternative anchoring group for Dye - Sensitized Solar Cells

Dye-sensitized solar cells (DSSC) have been the subject of constant attention in recent years thanks to the enhancement in their efficiency and stability. Metal-free D-?-A dyes are especially interesting since their particular architecture allows a fine adjustment of their photo-and electrochemical properties and among the anchoring moiety, the alkoxysilane group was recently recognized as one of the most stable and high-performing anchoring units for DSSC. Our work focused on developing an alternative anchoring group to the siloxane, capable of showing the same interesting properties. Our choice has fallen upon the silatrane group. First, we studied an easy and versatile way to introduce the anchoring moiety and we successfully insert the group on three different molecular scaffolds by a simple amide coupling, in comparison for the corresponding trialkoxysilane compounds three different reactions were needed. Then, the spectroscopic properties and anchoring mode on nanocrystalline TiO2 of the silatrane-dyes were analyzed for a possible application in Dye Sensitized Solar Cells and these results were compared with those already obtained for the corresponding trialkoxysilane compounds.