Printable and Flexible Copper–Silver Alloy Electrodes with High Conductivity and Ultrahigh Oxidation Resistance

Printable and flexible Cu-Ag alloy electrodes with high conductivity and ultrahigh oxidation resistance have been successfully fabricated by using a newly developed Cu-Ag hybrid ink and a simple fabrication process consisting of low-temperature precuring followed by rapid photonic sintering (LTRS). A special Ag nanoparticle shell on a Cu core structure is first created in situ by low-temperature precuring. An instantaneous photonic sintering can induce rapid mutual dissolution between the Cu core and the Ag nanoparticle shell so that core-shell structures consisting of a Cu-rich phase in the core and a Ag-rich phase in the shell (Cu-Ag alloy) can be obtained on flexible substrates. The resulting Cu-Ag alloy electrode has high conductivity (3.4 μΩ·cm) and ultrahigh oxidation resistance even up to 180 °C in an air atmosphere; this approach shows huge potential and is a tempting prospect for the fabrication of highly reliable and cost-effective printed electronic devices.