A Universal Fluorinated Polymer Acceptor Enables All-Polymer Solar Cells with >15% Efficiency

Abstract

While great progress has been achieved in all-polymer solar cells (all-PSCs), the efficiency of all-PSCs is primarily limited by polymer acceptors that lack a high extinction coefficient, high electron mobility, and good compatibility with polymer donors. Here we designed and developed a polymer acceptor PFA1 based on a non-fullerene acceptor framework with a fluorine substituent on the 1,1-dicyanomethylene-3-indanone unit. In combination with an electron-donating polymer, PTzBI-oF, the blend film presents an extended and intensified absorption profile, enhanced electron mobility, and favorable film morphology. The optimized all-PSCs exhibit a remarkably high efficiency of 15.11%, which is, to the best of our knowledge, the highest performance yet reported for an all-PSC. Of particular importance is the applicability of PFA1 as a universal polymer acceptor with a range of polymer donors to achieve impressively high efficiencies. These properties enable a new molecular design strategy for the construction of polymer acceptors toward applications in high-performance all-PSCs.