Room-Temperature Sintering of Tri‑n‑Octylphosphine-Oxide-Capped Silver Nanoparticle Paste by Dipping into an Organic Solvent Containing a Sintering Agent

We successfully developed a novel method for room-temperature (RT) sintering of silver nanoparticle (Ag NP) paste under an air atmosphere. A nonaqueous paste consisting of tri-n-octylphosphine oxide (TOPO) and TOPO-capped Ag NPs was prepared by the ligand exchange method. Then the paste was cast on the PET substrate and sintered at RT by dipping into an organic solvent containing a sintering agent. The experimental conditions such as sintering agent, dipping time, dipping solvent, and ligand of Ag NP were examined for optimizing the RT sintering. The electrical resistivity of the Ag thin films obtained in this study was about 10^–5 Ω m, which was comparable to that of the Ag thin film prepared by the thermal sintering. The chemical composition of the Ag thin films characterized by X-ray photoelectron spectroscopy and X-ray diffraction showed the formation of pure Ag films.