Asymmetric 8H-Thieno[2',3':4,5]thieno[3,2-b]thieno[2,3-d]pyrrole-Based Sensitizers: Synthesis and Application in Dye-Sensitized Solar Cells.

Asymmetric 8H-thieno[2',3':4,5]thieno[3,2-b]thieno[2,3-d]pyrrole (TTP) unit has been synthesized and used as a rigid and coplanar π-bridge to construct four new metal-free sensitizers W05-08. These dyes sensitized solar cells exhibit high photocurrent due to strong light harvesting capability. Among these dyes, the W05-based cell in conjunction with cobalt(II/III) redox shuttle exhibits the best power conversion efficiency up to 9.22%.