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 cm(2) with high efficiencies of 7.67% and 9.15%, respectively, are achieved.