The Study On Organic-encapsulated Silver Nanoparticles For Flexible Electronics And Ink-jet Printing Technology

With the rapid development of electronic technology, electronic products have become smaller, lighter and thinner. The traditional electronic products can not meet the requirements of mobile electronic products. Flexible circuits have received tremendous attention in recent years. However, in the process of overall commercial industrialization, flexible electronics still have many technical difficulties, such as the synthesis and preparation of the metal electrode materials on the organic polymer thin film. These metals typically demand traditional semiconductor metallization and high-temperature (200-300℃) annealing processes to form high-quality conductors on the organic active layers. It has been found that the annealing temperature of 200-300℃ may be too high for many organic thin films and could reduce the device quantum efficiency and reliability by introducing a large density of killer defects, such as dark spot defects, at the metal/organic interfaces. So it is necessary to develop a new class of metal thin film that can be synthesized and used at normal pressure and temperature.The microemulsion method was employed to prepare silver nanoparticles. Sodium borohydride and tetraethylene glycol monododecyl ether were used as reducing agent and nonionic surfactants, respectively. Meanwhile hexanethiol was added as the organic encapsulant. Organic encapsulated silver nanoparticles with high purity and small size were prepared through simple process. The size of silver nanoparticles could be controlled by the amount of hexanethiol. The hexanethiol was sublimated by annealing, at the same time; the silver nanoparticles were melted to form thin film which showed good electrical conductivity.Finally, we prepared nano-silver ink for ink jet printing using the above silver nanopariticles. We tried two different solvent and found ethanol to be better than water.