π–π Stacking Modulation via Polymer Adsorption for Elongated Exciton Diffusion in High‐Efficiency Thick‐Film Organic Solar Cells

Developing efficient organic solar cells (OSCs) with thick active layers is crucial for roll-to-roll printing. However, thicker layers often result in lower efficiency. This study tackles this challenge using a polymer adsorption strategy combined with a layer-by-layer approach. Incorporating insulator polystyrene (PS) into the PM6:L8-BO system creates PM6+PS:L8-BO blends, effectively suppressing trap states and extending exciton diffusion length in the mixed donor domain. Adding insulating polymers with benzene rings to the donor enhances π-π stacking of donors, boosting intermolecular interactions and electron wave function overlap. This results in more orderly molecular stacking, longer exciton lifetimes,…

• SU
  Shandong University

  Award: 2104573S
• AC
  Analytical Center for the Government of the Russian Federation
• NN
  National Natural Science Foundation of China

  Award: 52073162
• NS
  Natural Science Foundation of Shandong Province

  Awards: CE170100026, ZR2019ZD43
• CO
  Centre of Excellence in Exciton Science

  Award: CE170100026