Electrical Sintering of Silver Nanoparticle Ink Studied by In-Situ TEM Probing

Abstract

Metallic nanoparticle inks are used for printed electronics, but to reach acceptable conductivity the structures need to be sintered, usually using a furnace. Recently, sintering by direct resistive heating has been demonstrated. For a microscopic understanding of this Joule heating sintering method, we studied the entire process in real time inside a transmission electron microscope equipped with a movable electrical probe. We found an onset of Joule heating induced sintering and coalescence of nanoparticles at power levels of 0.1–10 mW/ m³. In addition, a carbonization of the organic shells that stabilize the nanoparticles were found, with a conductivity of 4 10⁵ Sm⁻¹.