Silver Nanowire Electrodes Integrated in Organic Solar Cells with Thick Active Layer Based on a Low-Cost Donor Polymer

Transparent electrodes are a key component in the manufacturing of optoelectronic devices such as light-emitting diodes, touch screens, and solar cells. The transparent electrode commonly used in this field is based on indium tin oxide (ITO). It contains indium, which is an expensive, rare, difficult to extract, and depleting element, hence the need to find an alternative. Silver nanowire (AgNW) electrodes are one of the best alternatives due to their excellent electrical, optical, and mechanical properties. Herein, it is shown that embedding AgNWs between two layers of ZnO nanoparticles (ZnONPs) leads to superior optical and electrical performance. The validation of the ZnONPs/AgNWs/ZnONPs electrode using the reference PF2:PC70BM organic active layer, known to present a long carrier lifetime, in inverted solar cell architectures shows an increased absorption of the active layer. This enhancement is due to the electrical field resulting from plasmonic resonance because the absorption is proportional to the square of the electric field amplitude. Through photoluminescence spectroscopy, a shorter exciton lifetime in PF2 in the presence of AgNWs is also observed. All these processes lead to improved photovoltaic performance compared to ITO-based reference, with approximately 20% increase in photocurrent and overall power conversion efficiency.