A new approach for additive-free room temperature sintering of conductive patterns using polymer-stabilized Sn nanoparticles†
Tin nanoparticles (Sn NPs) are of considerable interest for conductive printing because of their low melting temperature and low cost. In the present study, polyvinylpyrrolidone (PVP) stabilized metallic Sn NPs were synthesized by a polyol process and the size of Sn NPs was controlled from 15 to 89 nm by adjusting the amount of PVP. For the first time, we demonstrated that conductive patterns fabricated from the inks of metallic Sn NPs were achieved readily at room temperature under N2 without reducing gases or additives. The lowest obtained resistivity was 1.1 × 10−3 Ω cm, which was 100 times higher than that of bulk Sn. The size of Sn NPs, the amount of the stabilizing agent, and the low melting temperature of Sn NPs were found to be the main factors controlling the conductivity of the obtained Sn pattern in room temperature sintering. This study offers a new approach for the room temperature fabrication of conductive electronics using the printing technique.