Faculty Sponsor's Department:
Due to the increasing demand for flexible transparent conductors, alternative materials have been investigated. In fact, the leading material, Indium Tin Oxide (ITO) is very scarce and brittle, making it non ideal for cheaper and flexible transparent conductors. During this summer project, a silver nanowire (Ag NW) ink was synthesized and deposited on thin films as a replacement for ITO. The Ag NWs were grown by a seed mediated solution-based polyol process, where a diol, ethylene glycol, reduces a metal salt precursor. Once the nanowires formed, they were washed several times in a mixture of solvent and redispersed in water. A polymer, alginic acid sodium salt, was added to the mixture to form the nanowire ink. The nanowires were deposited on glass and two different polymers, PET and PEN. Three studies were conducted to optimize the deposition process. The first goal was to optimize the viscosity of the ink by changing the weight percentage of the alginic acid. Next the nanowire films were annealed on a hot plate and an oven to fuse the nanowire junctions. Finally the nanowire concentration was varied to achieve the percolation threshold. Films were characterized using a four point probe to measure sheet resistance, a UV-Visnir microscope to measure transmittance, and an SEM to take images of the nanowires.