A Green Approach for High Oxidation Resistance, Flexible Transparent Conductive Films Based on Reduced Graphene Oxide and Copper Nanowires

Abstract

Copper nanowires (CuNWs)-based thin film is one of the potential alternatives to tin-doped indium oxide (ITO) in terms of transparent conductive films (TCFs). However, the severe problem of atmospheric oxidation restricts their practical applications. In this work, we develop a simple approach to fabricate highly stable TCFs through the dip-coating method using reduced graphene oxide (rGO) and CuNWs as the primary materials. Compared with previous works using toxic reduction agents, herein, the CuNWs are synthesized via a green aqueous process using glucose and lactic acid as the reductants, and rGO is prepared through the modified Hummers’ method followed by a hydrogen-annealing process to form hydrogen-annealing-reduced graphene oxide (h-rGO). In the rGO/CuNWs films, the dip-coated graphene oxide layer can increase the adhesion of the CuNWs on the substrate, and the fabricated h-rGO/CuNWs can exhibit high atmospheric oxidation resistance and excellent flexibility. The sheet resistance of the h-rGO/CuNWs film only increased from 25.1 to 42.2 Ω/sq after exposure to ambient atmosphere for 30 days and remained almost unchanged after the dynamic bending test for 2500 cycles at a constant radius of 5.3 mm. The h-rGO/CuNWs TCF can be not only fabricated via a route with a superior inexpensive and safe method but also possessed competitive optoelectronic properties with high electrical stability and flexibility, demonstrating great opportunities for future optoelectronic applications.

Improving the Performance of Transparent Conducting Electrodes Based on Cu Nanowires

“…Tong et al [28], suggest enhancing the stability of CuNWs through the application of an in situ carbon protective layer coating. Lin et al [29], devised a straightforward method for producing stable TCEs by employing the dip-coating technique with reduced graphene oxide (rGO). However, more coating methods and materials are still required, especially in comparing some materials as coating in fabricating the TCEs.…”

Copper Nanowire/Polydopamine-Modified Sodium Alginate Composite Films with Enhanced Long-Term Stability and Adhesion for Flexible Organic Light-Emitting Diodes

“…For example, CuNWs coated with inactive metals, such as Ni, Ag, and Au, were demonstrated to enhance the antioxidation performance, but the introduction of opaque metals has a negative impact on the optical properties. In addition, encapsulation of the CuNW with graphene coatings could contribute to the improvement of chemical stability. − However, incomplete coverage of graphene can significantly compromise its protective efficacy owing to the presence of defects and cracks. Hence, single-crystal graphene was preferred to provide a better protective effect for CuNWs because of its nearly perfect lattice .…”

Zinc Oxide-Encapsulated Copper Nanowires for Stable Transparent Conductors

“…This factor limits their practical applications; therefore, enhancing the stability of Cu NWs has become an important research direction at present. Some research efforts have led to improving the stability of Cu NWs [20][21][22]. Among these attempts, covering the Cu NWs with a dense protective layer is one of the most effective methods.…”