Printed Silver Grid Incorporated With PEIE Doped ZnO as an Auxiliary Layer for High-Efficiency Large-Area Sprayed Organic Photovoltaics

The aim of this study is to mitigate the loss of performance of organic photovoltaics when the device area is increased. We propose that performance reduction is a result of the poor transverse charge transport due to defects in the electron transport layer and the resistance of the transparent electrode. We modified the surface of a zinc oxide (ZnO) with ethoxylated polyethylenimine and successfully lowered the performance reduction from 30% to 15% based on two electron transport layers of ZnO and ethoxylated polyethylenimine (PEIE)-modified ZnO (ZnO/PEIE bilayer and ZnO:PEIE hybrid layer). We also deposited Ag grids on the indium-tin-oxide (ITO) substrate to facilitate transverse charge transport in the ITO.