Facile preparation of particle-free hybrid amine silver ink with synergistic effect for low-resistivity flexible films

Amine ligand, as one of the essential components of the Ag–amine complex, is necessary to reduce the sintering temperature and time of conductive inks. Herein, we report the facile preparation of hybrid amine conductive silver ink, mainly composed of silver oxalate–hybrid amine complex and methanol–acetone solvent. The synergistic effect of long-chain and short-chain amines enhances the uniformity of silver nanoparticles in the silver film. A uniformly conductive silver film is obtained by spin-coating as-prepared ink on the polyimide film, followed by thermal sintering. Then, the influence of butylamine content and sintering parameters on the physical properties and microstructure of silver film is systematically investigated. The resistivity of silver films, sintered at 170 °C for only 20 min, is found to be 6.71 μΩ·cm, which is four times higher than bulk silver. In addition, silver films after bending and adhesion test exhibit low resistivity and excellent adhesion. These results indicate that the hybrid amine conductive silver ink can provide promising opportunities for fabricating highly conductive flexible printed electronics at low temperatures in short times.