Film-formation dynamics coordinated by intermediate state engineering enables efficient thickness-insensitive organic solar cells

In this work, by adding a low-cost and volatile 1,3,5-tribromobenzene solid as a process-aid additive, a champion power conversion efficiency as high as 19.1% together with a remarkable fill factor of 80.7% is achieved based on the state-of-the-art PM6:L8-BO system.