Improvements in purification of silver nanowires by decantation and fabrication of flexible transparent electrodes. Application to capacitive touch sensors

Transparent flexible electrodes made of metallic nanowires, and in particular silver nanowires (AgNWs), appear as an extremely promising alternative to transparent conductive oxides for future optoelectronic devices. Though significant progresses have been made the last few years, there is still some room for improvement regarding the synthesis of high quality silver nanowire solutions and fabrication process of high performance electrodes. We show that the commonly used purification process can be greatly simplified through decantation. Using this process it is possible to fabricate flexible electrodes by spray coating with sheet resistance lower than 25 Ω sq^-1 at 90% transparency in the visible spectrum. These electrodes were used to fabricate an operative transparent flexible touch screen. To our knowledge this is the first reported AgNW based touch sensor relying on capacitive technology.