A novel method of synthesizing antioxidative copper nanoparticles for high performance conductive ink

Due to low melting temperature, low price and high conductivity, copper nanoparticles have great potential to substitute conductive polymers, silver and gold nanoparticles and others in conductive inks. Here we developed a new, simple and green method to synthesize copper nanoparticles, which have the average size of around 140 nm and show remarkable ability to prevent oxidation. Using the copper nanoparticles for conductive ink, the electrical performance of copper film by depositing copper ink on polyimide was also investigated with the sintering temperature from 150 to 400 °C. The electrical resistivity is around 17.0 μΩ cm under sintering temperature of 250 °C, and can reach as low as 5.7 μΩ cm under the temperature of 400 °C. The proposed approach to synthesize copper nanoparticles for high performance conductive ink presents potential applications in flexible electronics.