Synthesis of oxidation-free copper nanowires toward solution-processed flexible and foldable electrodes

Z. Yin, S. Cho, J. Yoo, S.J. Lee, J.M. Myung, Y.S. Kim, Y.S. Kim
Seoul National University, KR

Keywords: Cu nanowire, Cu nanorod, metal ink, conductive ink


Herein, we introduce the novel synthesis of oxidation-free and single-crystalline Cu Nanowire(NW)s toward solution-processed flexible and foldable electrodes (SFFEs)by a salt-assisted polyol reduction method through control the structure-induced factors of capping ratio and nucleation rate. In addition, our method for Cu NWs successfully gives solutions for the previously mentioned problems, such as the rapid oxidation, the poor dispersion-ability, expensive catalyst and a long reaction time. The whole reaction time for the synthesis of Cu NWs was less than 2 hours without any catalysts. Also, the Cu NWs were well dispersed in isopropyl alcohol, preserved over 7 days without any oxidation, and easily re-dispersed in solvent after a short time shaking even passed a long time. The SFFEs, which were fabricated by these Cu NWs solution with a low temperature sintering process (180 ~ 220 °C), exhibited a high electrical performance (0.11 Ω/□), excellent flexibility and foldability even after 1000 time bending and all 90° folding due to their structure merits. As the synthesis of Cu NWs have several unique advantages, such as low sintering temperature, high oxidation resistance, and good dispersion-ability, we believe that they can easily apply to other substrates like a plastic or fabric.