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.