Inkjet printing of silver citrate conductive ink on PET substrate

Direct synthesis of silver conductive film on PET substrate by inkjet printing silver citrate conductive ink was presented in this paper. This kind of conductive ink contained silver citrate as silver precursor, 1,2-diaminopropane as complex agent dissolving the silver salt and methanol and isopropanol as a media adjusting the viscosity and surface tension. The formation of silver-amine complex reduced the decomposition temperature from 180 degrees C to 135 degrees C, thus the ink could be cured at relatively low temperature. The film reached the lowest resistivity of 17 mu Omega cm after cured at 150 degrees C for 50 min, 3.1 mu Omega cm at 230 degrees C and possessed high reflection and excellent adhesive property. Electrical conductivity, surface morphology and composition were investigated by four-point probe method, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). It is demonstrated how the cured condition affects the silver film. Moreover, radio-frequency identification (RFID) antenna was fabricated by inkjet printing, which opens up routes for the flexible electronics fabrication. (C) 2012 Elsevier B. V. All rights reserved.