Absorption Tuning of Monosubstituted Triazatruxenes for Bulk Heterojunction Solar Cells

A series of triazatruxene (TAT)-functionalized Bodipy dyes were prepared by a sequence of reactions involving either cross-coupling reactions promoted by Pd complexes or a Knoevenagel reaction leading to a vinyl linker. The new dyes show large absorption coefficients and fluorescence quantum yields as well as interesting electrochemical properties. The blue dyes of this series exhibit interesting photovoltaic effects (V OC = 0.83 V, J SC = 3.6 mA/cm2, efficiency 0.9%) in bulk heterojunction solar cells, due to the good hole mobility imported by the TAT entity.