Transparent electrodes based on silver nanowire networks: physical properties and potential applications

Transparent electrodes (TE) constitute a key component of optoelectronic devices such as solar cells, efficient organic light-emitting diodes (OLEDs), touch screens. Currently the most widely used TE is indium tin oxide (ITO), which offers low resistivity and high transparency in the visible. However the scarcity of indium and the lack of flexibility of ITO has prompted the search for alternative materials. Among emerging TE, metallic nanowire (NW) networks appear to be a promising solution since these percolating networks exhibit excellent properties with sheet resistance of a few Ω/sq and optical transparency of 90%, fulfilling the requirements for many applications. In addition, the fabrication of these electrodes involves low-temperature process steps and upscaling methods, thus making them very appropriate for future use as TE for flexible devices. Our research is focused on both the fabrication of TE based on silver NW and the optimization of their physical properties, using experimental and modelling approaches. The influence of several key parameters such as network density, silver NW dimensions as well as thermal annealing, on the networks physical properties is thoroughly explored. A comprehensive understanding of the relationship between design and main physical properties of these promising nanostructured networks will be presented. Their stability will also be discussed. Finally, we will also show that such TE can be very well adapted as transparent heaters