Crystal-to-crystal conversion of Cu₂O nanoparticles to Cu crystals and applications in printed electronics

In order to realize copper-based electrode materials for printed electronics applications, it is necessary to control the oxidation reaction during the sintering process. Here we report a novel approach based on the conversion process of cuprous oxide (Cu₂O) nanoparticle aggregates (NPAs) to metallic copper crystals. The NPAs undergo crystal conversion to copper crystals in air with the help of surfactants and a reducing agent. This crystal conversion is a very unique phenomenon which has not been observed previously. The detailed mechanism for this conversion, including the role of the surfactant and crystal growth, was proposed. Furthermore, we tried to realize oxidation free copper electrode formation in air by using the crystal conversion of Cu₂O NPAs.