Benzotrithiophene Co-polymers with high charge carrier mobilities in field-effect transistors

The successful design and synthesis of two novel benzo[1,2-b:3,4-b′: 5,6-d′]trithiophene-containing polymers is presented. The planar benzotrithiophene core induces strong aggregation effects in alternating co-polymers with both thiophene and thieno[3,2-b]thiophene. Co-monomer choice is found to play a crucial role in determining the backbone conformation, the interchain interactions, and the polymer solubility. Despite molecular disorder introduced by a branched solubilizing alkyl chain and a regiorandom polymerization of the asymmetric benzotrithiophene unit, these co-polymers exhibit hole mobilities as high as 0.24 cm²/(V s).