Transparent electrodes based on silver nanowires and carbon nanotubes for touch panels

We report about the production of transparent electrodes based on silver nanowires and on hybrid films consisting of silver nanowires and carbon nanotubes. An easy and scalable dip-coating method has been applied for conventional smart phone glass as substrate. After scratch-lithography we found our coating technique to be homogenous with regard to the electrical film conductivity and optical transmission. Annealing of the films causes significant decrease of the sheet resistance. We correlate the ideal annealing temperature with the diameter of the silver nanowires and carry out scanning-force microscopy at the junction points. Adding carbon nanotubes to the silver nanowire network can increase the film conductivity significantly. This effect is the most distinct near the percolation threshold and depends on the aspect ratio of the silver nanowires. Our best performing transparent electrodes exhibit a sheet resistance of around 70 Ohms per square at optical transmission higher than 98 percent.