Push-pull type conjugated polymers have become a dominating class of active materials in the field of organic electronics. Their adjustable light-harvesting, charge transfer and transport characteristics have been beneficially applied in organic solar cells, photodetectors and thin-film transistors. The conventional synthetic approach toward these polymers is based on Suzuki or Stille cross-coupling of complementary functionalized heterocyclic precursors. In the ideal world, this should give rise to a perfect alternation of the employed building blocks throughout the polymer backbone, which leads to a substantial decrease of the bandgap. In recent years, however, it has become increasingly clear that the ‘real’ structure of these polymers is often quite different from the projected one. Structural imperfections can for instance result from homocoupling of two identical building blocks. Furthermore, the end groups are often also not those expected. These structural defects generally have a negative impact on the device performance and should therefore be avoided during material production. In the presented project, this challenge will be addressed by systematic evaluation and optimization of the structure of prototype push-pull polymers. Continuous flow chemistry will be applied as a versatile tool to screen reaction conditions in the quest for defect-free materials, simultaneously allowing (reproducible) upscaling and thereby facilitating the implementation in organic electronics.