The Effect of α-Branched Side Chains on the Structural and Opto-Electronic Properties of Poly(Diketopyrrolopyrrole-alt-Terthiophene).

ABSTRACT: Introducing solubilizing α-branched alkyl chains on a poly(diketopyrrolopyrrole-alt-terthiophene) results in a dramatic change of the structural, optical, and electronic properties compared to the isomeric polymer carrying β-branched alkyl side chains. When branched at the α-position the alkyl substituent creates a steric hindrance that reduces the tendency of the polymer to π-π stack and endows the material with a much higher solubility in common organic solvents. The wider π-π stacking and reduced tendency to crystallize, evidenced from grazing-incidence wide-angle X-ray scattering, result in a wider optical band gap in the solid state. In solar cells with a fullerene acceptor, the α-branched isomer affords a higher open-circuit voltage, but an overall lower power conversion efficiency a

SUBMITTER: Saes BWH 

PROVIDER: S-EPMC7702133 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature