Growth of Ultralong Ag Nanowires by Electroless Deposition in Hot Ethylene Glycol for Flexible Transparent Conducting Electrodes

摘要

High aspect ratio silver (Ag) nanowires with an average length of 25.4 μm and diameter of 102.8 nm were successfully prepared by electroless deposition in hot ethylene glycol (160°C) for 1 h in the presence of PVP. It was found that both PVP concentration and molecular weight significantly influence the morphology and yield of Ag nanowires in solution. Using PVP MW = 55,000, addition of lower amounts of PVP led to formation of large irregularly shaped Ag particles together with a few rod-like structures. Increasing PVP concentration generally resulted in longer and thinner Ag nanowires. On the other hand, low molecular weight PVP produced spherical Ag particles even at high PVP concentration. Ag nanowire flexible transparent conducting electrodes attained a sheet resistance of about 92.5Ω/sq at an optical transmittance of about 79.6% without any heat treatment. In addition, no significant change in optical and electrical properties was observed after several cycles of bending and adhesion test.