Silver nanowire purification and separation by size and shape using multi-pass filtration

Silver nanowire (AgNW) meshes produced by soft solution polyol synthesis offer a low-cost low-temperature solution deposited alternative to indium tin oxide (ITO) transparent conductors for use in solar cells. However, polyol synthesis typically produces both nanoparticles and nanowires during synthesis. Nanoparticles reduce optical transmission of nanowire meshes without any beneficial reduction to sheet resistance. This work describes a combined purification and separation multi-pass filtration process to efficiently remove nanoparticles from nanowire solutions before deposition. The filtered samples typically contains 86% nanowires (14% nanoparticles) compared to 67% nanowires in the standard centrifuge process and 55% nanowires in the original sample. The filtration method offers further benefits of reduced nanowire breakage and a generally lower sheet resistance after nanowire deposition.