Long-term electrically stable silver nanowire composite transparent electrode under high current density

Abstract

Silver nanowire (AgNW) network has been employed to many electronic devices as transparent electrode.However, the poor electrical stability under current has been seriously holding its practical application, and we still lack long-term electrically stable AgNW system to study the underlying fundamental of electrical failure. In this work, the electrical performance and failure mechanism of chitosan-ascorbic acid (Chi-AsA)/AgNW composite under current stress were thoroughly studied. The composite electrode maintained stability above 24000 h under high current density of 100 mA cm -1 . The main failure in AgNW composite is found to be a wave break perpendicular to the current rather than traditional uniform degradation across AgNW networks. More interestingly, the AgNWs in failed composite electrode kept their original smooth morphology excepting the crack area, while the AgNWs in pristine networks degraded to nanoparticles or became disconnected everywhere. The patterned AgNW composite in microscale exhibits similar long lifetime in resisting current stress as the bulk composite lm. The effect of over-coating position, electrical stress, temperature and over-coating materials on the electrical stability were studied. The over-coating layer of Chi-AsA is proven to suppress the silver atoms from migration, reduce the concentrated Joule heating at junctions, and inhibit the corrosion. The Chi-AsA/AgNW composite enables electrically stable transparent conductor for next-generation optoelectronics, and the mechanism investigation may provide effective means of preparing electrically stable AgNW systems.

A review of silver nanowire-based composites for flexible electronic applications

“…GO encapsulation of Ag NWs was found to have a similar effect on the resistance by enhancing contact, thereby reducing the junction resistance and NW corrosion [254]. Mitigation of electromigration to improve the electric stability of Ag NW networks was also employed by a few other groups [255][256][257][258], wherein SWCNTs, GO, and chitosan-ascorbic acid were used to make composites with Ag NWs.…”

Time of Failure of Metallic Nanowire Networks under Coupled Electrical and Thermal Stress: Implications for Transparent Electrodes Lifetime

“…AgNWs can also be impacted by the flow of electrical current. , When AgNW networks undergo a low electrical stress, the main observation concerns the Joule heating effect that increases the network temperature over its entire area . For larger electrical stress, a failure mechanism is also observed, leading to the loss of electrical percolation of the network. − However, the destabilization of the nanowire morphology by spheroidization occurs locally, , contrarily to the thermal degradation under thermal stress. Even though both electrical and thermal failures show the same kind of AgNW degradation at the nanoscale, driven by the same Plateau–Rayleigh instability principle, their different phenomenology yields different macroscopic network degradation processes.…”

Silver Nanowire Networks Coated with a Few Nanometer Thick Aluminum Nitride Films for Ultra-Transparent and Robust Heating Applications

“…6,14−16 Despite the very promising results achieved so far thanks to such protective layers, there is still much room to improve the voltage and/or temperature of failure and to overcome limitations regarding the loss of optical transparency and long-term stability. 12,14,17,18 T h i s c o n t e n t i s It is thus worth exploring other materials to encapsulate AgNW networks. In this context, Patil et al recently introduced the use of oxynitrides as a protective coating.…”

“…Over the past decade, research of emerging transparent conductive materials (TCMs) has grown exponentially, thanks to their remarkable properties and the exciting opportunities they can provide to a large variety of devices, i.e., touch screens, smart windows, organic photovoltaics, energy harvesters, transparent heaters (THs), or biomedical sensors. − In the race to replace indium tin oxide (ITO), which is limited by film brittleness and scarcity of indium, metallic nanowire networks and grids, graphene-based thin films, conductive polymers, and several composite materials have demonstrated excellent electrical, optical, and mechanical properties. ,− Among them, AgNW networks are one of the most promising alternatives since they can be fabricated in open air and using large-scale deposition processes, and they have superior flexibility compared to ceramic transparent conductive oxides (TCOs). − However, there are crucial stability issues (chemical, thermal, and electrical) that have hindered their mass integration in devices. − A common strategy to improve the stability of AgNW networks has been to their encapsulation with a protective layer (typically metal oxides, graphene oxide, or polymer-based thin films) to prevent chemical reactions with the environment and silver atomic diffusion. ,− Despite the very promising results achieved so far thanks to such protective layers, there is still much room to improve the voltage and/or temperature of failure and to overcome limitations regarding the loss of optical transparency and long-term stability. ,,, …”