Self-Assembled In₂O₃ Nanoshells on Cu Nanowires by Vacuum-Free Processing for Highly Stable Transparent Conductive Films

The research on transparent electrodes based on copper nanowires (Cu NWs) has consistently garnered widespread interest due to their excellent flexibility and conductivity. The practical application of Cu NWs in electronic devices is severely hampered by their susceptibility to oxidation in air. Herein, we present a simple, cost-effective, and entirely solution-based approach for the self-assembled growth of indium oxide nanoshells on Cu NW surfaces. This technique enhances the photoelectric properties, as well as the thermal and chemical stability of the Cu NWs. In the presence of water molecules, the chemical reaction between In3+ and Cu atoms occurs, and a reasonable model for the formation of indium oxide is constructed. The Cu NWs@In2O3 network covered with In2O3 nanoshells obtained in this study demonstrates a minimal sheet resistance of 20.6 Ω/sq, along with an optical transmittance of 84.4%. Moreover, the Cu NWs@In2O3 conductive electrode exhibits outstanding stability under various extreme conditions, such as intense oxidation, elevated temperatures, and high humidity, with performance comparable to that of silver nanowires. Crucially, by taking advantage of the excellent mechanical and chemical stability of the Cu NWs@In2O3 electrode, we employed a transparent heating device to illustrate the practical application of transparent conductors.