ZnO Electron Transport Layers for Scalable Nonfullerene Acceptor-Based Organic Photovoltaics: Assessing the Role of Processing Technique on Device Performance and Stability.

and a maximum power conversion efficiency (PCE) of 13.8%. Furthermore, green solvent and ambient air slot-die coated OPVs employing sputtered ZnO ETLs reached an average PCE of 13.9%, demonstrating the scalability of the method. Importantly, the sputtered ZnO-based devices also exhibited superior long-term stability, showing only a 10% drop in PCE after 1000 h upon exposure to illumination. These improvements are attributed to reduced shunt pathways and mitigated trap-assisted recombination, yielding stability comparable to those based on high-quality atomic layer deposited ZnO ETLs. Moreover, OPVs with sputtered ZnO consistently outperform those with solution-processed ZnO ETLs for other active layer systems, demonstrating the highest PCE of 15.9% for inverted PM6:L8-BO devices. This work highlights the potential of sputter-deposited ZnO ETLs for large-scale inverted OPVs with exceptional efficiency and stability.