Large‐Area Flexible Organic Photovoltaic Modules on Smoothened Silver Nanowire Transparent Electrodes with Thick Electron Transporting Layer

Abstract High‐efficiency large‐area flexible organic photovoltaic (OPV) modules are still challenging. Electrical shunt and shortage generally occur due to surface roughness or spikes that result in low efficiency. In this work, a thick electron transporting layer (ETL) of zinc‐chelated polyethylenimine (PEI‐Zn) is introduced to smoothen the surface of silver nanowires (AgNWs) transparent electrodes. The smoothened surface of AgNWs electrodes helped to suppress the electrical leakage or shortage. Thicker PEI‐Zn layers are required to overcome the open‐circuit voltage ( V OC ) loss when the device area increases. For large‐area OPV modules on AgNWs electrodes, a high thickness of PEI‐Zn up to 350 nm can deliver high V OC as well as power conversion efficiency (PCE). Based on the AgNWs transparent electrode coated by thick PEI‐Zn ETL, a PCE of 12.50% is achieved for 35.2 cm 2 flexible OPV modules certified by a third party. The modules exhibited good illumination stability and mechanical flexibility.