Laser-induced shock wave sintering of silver nanoparticles on flexible substrates

Abstract

With the ever-increasing demand for lightweight, small, flexible, and portable devices, solving problems such as film cracking, delamination, and substrate damage has become a key issue in the direct fabrication of metal nanoparticle thin films on flexible substrates. In this work, we propose a method to sinter silver nanoparticles mechanically on heat-sensitive polymer substrates using a laser-induced shock wave generated by pulsed-laser ablation of a sacrificial layer. Physical mechanisms involved in silver nanoparticle sintering and properties of the sintered film were experimentally analyzed. Sintering of silver nanoparticles occurred predominantly by surface necking through solid-state atomic diffusion. In terms of density and electrical conductivity of the sintered films, the method shows substantially better sintering performance than typical sintering methods. Under optimal condition, near-full-density silver films were produced with an electrical resistivity as low as similar to 2.7 mu Omega.cm . Consequently, this work demonstrates that the proposed laser-induced shock pressing technique has good potential for the fabrication of high-density metal films and patterns on heat-sensitive flexible substrates with exceptional film properties.