Delayed Crystallization Kinetics Allowing High‐Efficiency All‐Polymer Photovoltaics with Superior Upscaled Manufacturing

Abstract Though encouraging performance is achieved in small‐area organic photovoltaics (OPVs), reducing efficiency loss when evoluted to large‐area modules is an important but unsolved issue. Considering that polymer materials show benefits in film‐forming processability and mechanical robustness, a high‐efficiency all‐polymer OPV module is demonstrated in this work. First, a ternary blend consisting of two polymer donors, PM6 and PBQx‐TCl, and one polymer acceptor, PY‐IT, is developed, with which triplet state recombination is suppressed for a reduced energy loss, thus allowing a higher voltage; and donor–acceptor miscibility is compromised for enhanced charge transport, thus resulting in improved photocurrent and fill factor; all these contribute to a champion efficiency of 19% for all‐polymer OPVs. Second, the delayed crystallization kinetics from solution to film solidification is achieved that gives a longer operation time window for optimized blend morphology in large‐area module, thus relieving the loss of fill factor and allowing a record efficiency of 16.26% on an upscaled module with an area of 19.3 cm 2 . Besides, this all‐polymer system also shows excellent mechanical stability. This work demonstrates that all‐polymer ternary systems are capable of solving the upscaled manufacturing issue, thereby enabling high‐efficiency OPV modules.