(375a) Copper-Silver Core-Shell Nanoparticles for Conductive Ink

As the printed electronics technology rapidly developed, there is an increasing need for lowing the cost of electronic conductive ink. Copper nanoparticles can be utilized as a low-cost replacement for silver nanoparticles which are currently used in the commercial conductive ink. However, the main obstacle for using copper nanoparticles is their spontaneous oxidation at ambient conditions. In this work, we prepared the uniform Cu-Ag core-shell nanoparticles with a particle size of 12.6nm using a novel two-step process, which consists of the thermal decomposition of Cu complex and the galvanic displacement of Cu with Ag. HR-TEM and EDS confirm the core-shell structure and particle size. XRD analyses confirm that the Cu-Ag nanoparticles have considerably higher oxidation stability than Cu nanoparticles. The prepared Cu-Ag core-shell nanoparticles is used to formulate the conductive ink, and then to form the conductive pattern on the substrate. The results showed that the resistivity of Cu-Ag line on polyimide film obtained from the nano-Cu-Ag ink was low to 15μΩ•cm. To verify the continuity of conductive pattern, we demonstrated the lighting of LED when conductive track was connected to 3V battery.