Achieving an excellent efficiency of 11.57% in a polymer solar cell submodule with a 55 cm2 active area using 1D/2A terpolymers and environmentally friendly nonhalogenated solvents

The transition of polymer solar cells (PSCs) from laboratory‐scale unit cells to industrial‐scale modules requires the development of new p‐type polymers for high‐performance large‐area PSC modules based on environmentally friendly processes. Herein, a series of 1D/2A terpolymers (PBTPttBD) composed of benzo[1,2‐b:4,5‐b’]dithiophene (BDT‐F), thieno[3,4‐c]pyrrole‐4,6(5H)‐dione (TPD‐TT), and benzo‐[1,2‐c:4,5‐c’]dithiophene‐4,8‐dione (BDD) is synthesized for nonhalogenated solvent processed PSC submodules. The optical, electrochemical, charge‐transport, and nano‐morphological properties of the PBTPttBD terpolymers are modulated by adjusting the molar ratio of the TPD‐TT and BDD components. PBTPttBD‐75:BTP‐eC11‐based PSC submodules, processed with o‐xylene, achieve a notable PCE of 11.57% over a 55 cm2 active area. This PCE value is among the highest reported using a nonhalogenated solvent over a 55 cm2 active area module. The optimized PSC submodule exhibits minimal cell‐to‐module loss, which can be attributed to the optimized crystallinity of the PBTPttBD‐75:BTP‐eC11 photoactive layer system and favorable film formation kinetics. A new series of 1D/2A PBTPttBD terpolymers has been developed for room‐temperature and nonhalogenated solvent processed polymer solar cell (PSC) submodules. A PBTPttBD‐75:BTP‐eC11 PSC submodule, processed with o‐xylene, achieves a notable efficiency of 11.57% over a 55 cm2 active area, which is among the highest reported using nonhalogenated solvents.