Large-Area Gravure-Printed AgNWs Electrode on Water/Oxygen Barrier Substrate for Long-Term Stable Large-Area Flexible Organic Solar Cells

Large-area AgNWs electrodes (25 cm x 10 cm) were fabricated through roll-to-roll printing on the polyvinyl alcohol (PVA) modified water and oxygen barrier substrate. The modification of the barrier film with PVA improved the wettability of silver nanowires on the barrier films and led to the formation of homogenous large-area AgNWs networks. The mechanical flexibility, especially the adhesion force between the silver electrode and the barrier film substrate was dramatically improved through PVA modification. The efficiency of 13.51% for the flexible OSCs with an area of 0.64 cm(2) was achieved based on the PET/barrier film/PVA/AgNWs electrode. The long-term stability showed the flexible OSCs based on the PET/barrier film/PVA/AgNWs electrode have a significantly improved stability relative to the device on PET/AgNWs electrode, and comparable air stability as the rigid device with glass/ITO device. The unencapsulated devices maintained nearly 50% of the original efficiency after storage for 600 h in air. After a simple top encapsulation, the flexible devices remained at 60% of the initial efficiency after 2000 h in the air. Therefore, the flexible AgNWs electrode based on the barrier film would have the potential to improve the air storage stability of organic flexible solar cells.