Abstract
Silver nanowire (AgNW) films have been shown to have transparent and conductive properties suitable to replace indium tin oxide (ITO) in applications such as touch sensors. However few studies have been conducted to investigate how these films may be processed to produce functional devices on a manufacturing scale. In this study, methods of optimising the transparent conductive properties of AgNW films made from commercially available nanowire sources, while minimising processing costs are considered. Rinsing and heating films post deposition yield films of a higher transmission at a set sheet resistance of 100 ohms per square (Ω/□), and reduce the required volume of nanowires by up to 45%, reducing material costs. These films are then processed by laser ablation to demonstrate successful electrical isolation can be achieved in geometries with dimensions as low as 45 μm, at laser fluences less than 25% of that required for processing ITO. However, confining the dimensions of the AgNW tracks can increase sheet resistance locally, compared to that of the unprocessed films, at dimensions commonly used in touch sensors. Despite this, working single sided five inch sensors are fabricated by laser ablation, with sensitivity, charge time and scribe visibility comparable to that of the same design of sensor on ITO. The lifetime of these nanowire devices is then considered, looking in to the effects of high voltage electrical discharge through the device, migration of material when in operation at high temperature and humidity and degradation due to exposure to air. Overcoats are employed to limit damage, with four candidates showing benefits. However, failure of sensors due to electrostatic discharge testing could not be prevented.