Importance of Optimal Crystallinity and Hole Mobility of BDT‐Based Polymer Donor for Simultaneous Enhancements of V_oc, J_sc, and FF in Efficient Nonfullerene Organic Solar Cells

In this work, a new series of polymer donors consisting of thienothiophene π‐bridged N ‐octylthieno[3,4‐ c ]pyrrole‐4,6‐dione (8ttTPD) and benzo[1,2‐ b :4,5‐ b ']dithiophene (BDT) units for producing highly efficient organic solar cells (OSCs) paired with a Y6 acceptor is developed. The incorporation of the highly planar 8ttTPD unit enhances crystalline properties as well as hole mobilities of the BDT‐based polymers that typically have amorphous...