Fibrillization of Non‐Fullerene Acceptors Enables 19% Efficiency Pseudo‐Bulk Heterojunction Organic Solar Cells

The structural order and aggregation of non-fullerene acceptors (NFA) are critical toward light absorption, phase separation, and charge transport properties of their photovoltaic blends with electron donors, and determine the power conversion efficiency (PCE) of the corresponding organic solar cells (OSCs). In this work, the fibrillization of small molecular NFA L8-BO with the assistance of fused-ring solvent additive 1-fluoronaphthalene (FN) to substantially improve device PCE is demonstrated. Molecular dynamics simulations show that FN attaches to the backbone of L8-BO as the molecular bridge to enhance the intermolecular packing , inducing 1D self-assembly of L8-BO into fine fibrils with a compact…

• NN
  National Natural Science Foundation of China

  Awards: 52273196, 52073221
• FR
  Fundamental Research Funds for the Central Universities

  Awards: 2020‐YB‐004, 2021III016JC