Solution-Processed Low Resistivity Zinc Oxide Nanoparticle Film with Enhanced Stability Using EVOH

This paper proposes a solution-based fabrication process of the zinc oxide nanoparticle (ZnO NP) film. It achieves a resistivity comparable to that of ZnO deposited by using physical and chemical vapor deposition methods. The process involves exposing the solution-processed ZnO NP film to 365 nm ultraviolet light and passivating it with an ethylene vinyl alcohol (EVOH) encapsulant of 80 μm under a vacuum. The manufacturing process has a maximum temperature of 190 °C, enabling use on flexible substrates, such as polyimide. The fabricated ZnO film has a sheet resistance of 2.5 × 104 Ω/□ and a thickness of 2.35 μm. The EVOH passivation layer enhanced the film stability, protecting it when exposed to the ambient environment. The resistivity of the ZnO NP layer with EVOH passivation remains unchanged after 60 days in an ambient environment.