Sintering of inkjet-printed silver nanoparticles by large-area atmospheric pressure nitrogen plasma

Silver nanoparticles were sintered at atmospheric pressure using nitrogen plasma generated by diffuse coplanar surface barrier discharge (DCSBD). Compared to the standard thermal sintering of 1 h at 140 degrees C only 8 min of nonthermal plasma treatment at 50 degrees C were necessary to sufficiently anneal the silver nanoparticle film. Electrical resistivity as low as 9 x 10-6 Omega cm was achieved, i.e., 17% of the bulk conductivity of silver. X-ray photoelectron spectroscopy was used to study the removal of organic moieties from the surface of the inkjet-printed layers. Scanning electron microscopy revealed in detail the process of formation of interconnection between nanoparticles. Our findings pave the way for implementing low-cost and eco-friendly DCSBD plasma sintering into continuous roll-to-roll processing in the future for the annealing of silver nanoparticles on substrates that cannot tolerate high temperatures.