Acceptor Crystallinity Engineering Enables >20% Efficiency Binary Organic Solar Cells with 83.0% Fill Factor

For spontaneously crystallized organic photovoltaic materials, morphology optimization remains a challenge due to the disparity in crystallinity between the donor and acceptor components. Imperfections in the crystalline phases result in significant trap-assisted recombination, which emerges as a critical factor limiting the fill factor (FF) of organic solar cells (OSCs). Herein, a method is introduced for precise regulation of the acceptor crystallinity, utilizing a novel upper-layer acceptor processing solvent, trichloroethylene (TCE), to improve the state and vertical morphology of the active layer. The TCE solvent synergistically optimizes intermolecular interactions among acceptor molecules and balances…

• NN
  National Natural Science Foundation of China

  Award: 52333005
• NS
  Natural Science Foundation of Beijing Municipality

  Award: Z230018