Soft Porous Blade Printing of Nonfullerene Organic Solar Cells.

Developing scalable and robust processing methods with low material waste remains a challenge for organic solar cells (OSCs) to become a practical renewable energy source. Here, we present a novel low-cost processing approach termed as soft porous blade printing (SPBP), which uses a layer of soft porous material such as filter paper as the printing blade. The inherent porous microstructure of the blade offers high shear rates that facilitate the alignment, crystallization, and orientation of active materials during printing. Moreover, by eliminating the suspended liquid meniscus, SPBP relaxes the stringent requirement of gap control and enables continuous ink delivery for uninterrupted film fabrication with adjustable thickness. Higher photovoltaic performances are achieved in the SPBP-printed OSCs than those of the spin-coated counterparts for two nonfullerene-acceptor active-layer systems (Y6:PM6 and PTQ10:IDIC). Y6:PM6 cells printed by SPBP without any additive exhibit power conversion efficiencies up to 14.75%, which is among the highest reported to date for non-spin-coated OSCs.