Challenges and Mitigation Pathways in Coating Silver Nanowire Networks with Metallic Oxides by Magnetron Sputtering

Abstract

Silver nanowire (AgNW) networks are leading transparent electrodes, but their integration into functional devices often requires coating with sputtered oxides, a step during which they can degrade. Here, we investigate the degradation of AgNW networks during RF magnetron sputtering by combining in situ electrical resistance monitoring with electron microscopy and X-ray diffraction, varying oxygen partial pressure, target material, plasma power, argon pressure, and buffer layers. Network failure is found to be abrupt, occurring within the first minutes of exposure, and to be governed by a coupled oxygen–target effect rather than by heating: oxygen in the discharge is necessary but not sufficient, the decisive factor being the ability of the target to generate energetic negative oxygen ions. Oxide or readily oxidized targets (e.g., WO3, W) systematically fragment the nanowires and drive the sheet resistance to infinity, whereas weakly oxidizing metals (Cu, Ni) preserve both morphology and resistance. Common mitigation routes for compact films─raising the argon pressure or lowering the power─prove insufficient, but a 30 nm ZnO buffer layer fully suppresses the damage. These results clarify the degradation mechanism and provide practical guidelines for integrating AgNW networks with sputtered functional oxides.