Overcoming the Low‐Surface‐Energy‐Induced Wettability Problem of Flexible and Transparent Electrodes for Large‐Area Organic Photovoltaic Modules over 500 cm²

Abstract To realize the commercialization of nonfullerene acceptor‐based efficient organic solar cells, a low‐cost and indium‐tin‐oxide‐free (ITO‐free) flexible electrode‐based module that can be produced by roll‐to‐roll production should be developed. However, the low surface energy of ITO‐free electrodes hinders the formation of a uniform charge transport layer through solution processing; this is the main cause of the efficiency drop. Herein, the realization of a highly uniform ZnO bilayer on an ultrathin Ag film‐based transparent electrode that is suitable for flexible substrates and large‐area organic photovoltaic (OPV) module fabrication is demonstrated. Based on the sputtered ZnO and blade‐coated ZnO nanoparticle‐based electron transport bilayer, large OPV module areas of 528.5 and 108 cm² with high efficiencies of 7.67% and 9.15%, respectively, are achieved.