The effect of direct amine substituted push–pull oligothiophene chromophores on dye-sensitized and bulk heterojunction solar cells performance

The effect of direct amine substitution on the photovoltaic performance of donor–acceptor oligothiophenes in dye-sensitized and bulk heterojunction (BHJ) solar cells was investigated. These dyes have a common donor (di-p-tolylamino), π-bridge (terthiophene), and tunable acceptors to provide new materials for evaluation in dye-sensitized solar cells (DSCs) and BHJ solar cells. They were tested with liquid, ionic liquid, and metal-complex based electrolytes for DSCs and PC61BM for solution processable BHJ solar cells. Direct amine substitution of the oligothiophene resulted in a significant spectral red-shift, reduction in band-gaps and improved photovoltaic performance in DSCs but not for BHJ devices.