Chuanhang Guo's work on cold-aging mediated NFA aggregation to reach a power conversion efficiency of 18% is accepted in Advanced Energy Materials.
This work reports a cold-aging strategy to mediate the pre-aggregation of PM6 polymer in solution through a disorder-order transition, which leads to dense and fine PM6 aggregates with enhanced p-p stacking in its blend thin films with either fused-ring and non-fused-ring non-fullerene acceptors (NFAs) including Y6-BO, N3, IT-4F and PTIC. The fine aggregates of PM6 and slightly enlarged NFA domains improve the continuous networks with enhanced and balanced charge mobility. The resulting OSCs all receive enhanced PCEs compared to their counterparts without any cold-aging treatments, with PM6:Y6-BO OSC being most effective from 16.6% to 17.7%. This can be further optimized upon casting of the cold-aging solution with the presence of solvent vapor, resulting in a champion PCE of 18.0% for PM6:Y6-BO OSC.