Zirconia-coated silver nanowire networks: enhancing transparency and stability via atmospheric pressure spatial ALD

Silver nanowires (AgNWs) are increasingly proposed as transparent conductive materials for flexible transparent electrodes (TEs) due to the tunability of their optical and electrical properties when assembled into percolating networks, as well as their superior mechanical flexibility compared to indium tin oxide (ITO). However, their main drawbacks are poor adhesion to substrates and intrinsic thermal, electrical and chemical instability, leading to degradation of network connectivity. A common strategy to mitigate these issues is the application of protective coatings to suppress surface reactions and diffusion. In this context, metal oxides (MO_x) have been widely demonstrated to effectively reduce Ag diffusion and address all stability issues (thermal, electrical and environmental). Herein, we present a novel approach using zirconium oxide (ZrO₂), a wide band-gap oxide, as a protective coating deposited by atmospheric pressure spatial atomic layer deposition (AP-SALD), a more time-efficient alternative to conventional ALD. The effects of coating thickness on stability enhancement and adhesion were systematically investigated. The results show that an ultrathin (3 nm) ZrO₂ overcoat acts as an effective diffusion barrier without compromising optical transmittance, outperforming other commonly studied metal oxides. Finally, the process was successfully demonstrated on flexible substrates, highlighting its potential for next-generation flexible electronic devices.