A nonfullerene acceptor as a solid additive realizing a record efficiency of 17.74% in quasi-layered all-polymer solar cells

The nonfullerene acceptor L8-BO as solid additive was incorporated into QLA-PSCs based on PM6 and PY-IT. The molecular orientation and exciton diffusion length in PY-IT layer can be optimized, resulting in the PCE enhanced from 16.14% to 17.74%.