Novel Synthesis, Coating, and Networking of Curved Copper Nanowires for Flexible Transparent Conductive Electrodes

In this work, a whole manufacturing process of the curved copper nanowires (CCNs) based flexible transparent conductive electrode (FTCE) is reported with all solution processes, including synthesis, coating, and networking. The CCNs with high purity and good quality are designed and synthesized by a binary polyol coreduction method. In this reaction, volume ratio and reaction time are the significant factors for the successful synthesis. These nanowires have an average 50 nm in width and 25-40 μm range in length with curved structure and high softness. Furthermore, a meniscus-dragging deposition (MDD) method is used to uniformly coat the well-dispersed CCNs on the glass or polyethylene terephthalate substrate with a simple process. The optoelectrical property of the CCNs thin films is precisely controlled by applying the MDD method. The FTCE is fabricated by networking of CCNs using solvent-dipped annealing method with vacuum-free, transfer-free, and low-temperature conditions. To remove the natural oxide layer, the CCNs thin films are reduced by glycerol or NaBH₄ solution at low temperature. As a highly robust FTCE, the CCNs thin film exhibits excellent optoelectrical performance (T = 86.62%, R _s = 99.14 Ω ^-1), flexibility, and durability (R/R ₀ < 1.05 at 2000 bending, 5 mm of bending radius). Curved copper nanowires (CCNs) are designed and synthesized by a binary polyol coreduction method. They are very soft and self-bendable. A CCN-based flexible transparent conductive electrode (FTCE) is fabricated by meniscus-dragging deposition and solvent-dipped annealing method with vacuum-free and transfer-free and low-temperature condition. The highly robust FTCE exhibits excellent electrical conductivity, transparency, flexibility, and durability.