SalenZn-bridged D-π-A Dyes For Dye-Sensitized Solar Cells

A series of SalenZn based dyes with triphenylamine derivatives as the donor, benzoic acid as the acceptor, and coplanar Salen complexes as the spacer have been designed and synthesized for dye-sensitized solar cells. The absorption, electrochemical, and photovoltaic properties for all sensitizers have been systematically investigated. When the tail length of the alkyl substituents is increased from C-0 to C-8 on the donor part, the efficiency of its DSSC augments evidently. It is found that the incorporation of bis-carboxyl groups instead of the single carboxyl group as anchoring groups induces a remarkable enhancement of the electron injection efficiency from the excited dyes to the TiO2 semiconductor and generates higher electron density and voltage.