Towards enhanced transparent conductive nanocomposites based on metallic nanowire networks coated with metal oxides: a brief review

Metallic nanowire networks (MNNs) are promising emerging transparent electrodes (TEs) in multiple application fields. In the last few years, they have been widely reported in the literature as they present attractive physical properties (both electrical and optical) while reducing the amount of required material with respect to conventional TEs, which makes them highly competitive in terms of cost, flexibility, and integrability. Despite all their virtues, MNNs have shown several drawbacks such as rapid degradation and limited capacity for fine-tuning the properties for each specific application. To overcome these issues, several coatings have been thoroughly studied, from polymers, carbonaceous materials, and oxynitrides, to metal oxides. Among these, metal oxides have been largely studied due to their large panoply of properties and different possible synthetic approaches. In this minireview, we provide an overview of the research on metal oxide-coated MNNs, with a particular focus on silver nanowire (AgNW) networks, as they are the most extensively studied. However, the discussion and conclusions drawn here can be directly applied to other metallic nanowires as well. Most importantly, we evaluate the impact of the coating on the fundamental properties and stability of these promising nanocomposites. Finally, a comprehensive overview of various applications based on these specific nanocomposites is presented, including photovoltaics, transparent heaters, smart windows, sensors, diodes, plasmonics, microelectronics, among others. This work offers insights into the potential applications of AgNW-metal oxide nanocomposites in the future and outlines the critical parameters of metal oxide coatings and their functionalities. This work will serve as a guideline towards designing more efficient metal oxide-MNNs through processes compatible with roll-to-roll mass manufacturing for industrial use.