Synthesis of colourless silver precursor ink for printing conductive patterns on silicon nitride substrates

Silver precursor ink was synthesised by a simple and environmentally friendly method based on chemical reduction. The stability, particle size, viscosity and surface tension of the ink were adjusted by adding polyvinylpyrrolidone (PVP) and ethylene glycol (EG). The silver patterns were fabricated on the silicon nitride substrate and were characterised by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrical measurements. The thickness of the sample printed three times was approximately 0.66 μm, and it increased to 2.43 μm after 12 printings. The ink-jet-printed silver patterns exhibited good conductivity when the samples were sintered at temperatures above 200 °C. The resistivity value was observed to decrease to 3.1 μΩ cm after sintering at 500 °C for 60 min, twice the value of bulk silver (1.6 μΩ cm). The low resistivity of silver patterns suggests applications for ink-jet printing of electronics devices.