Highly Conductive Nanoparticulate Films Achieved at Low Sintering Temperatures

Nanoparticulate Ag films have been produced by the laser ablation of microparticle aerosol (LAMA) deposition process. LAMA enables the production of thick, nanoparticulate films that are free of organics and offers the ability to control the degree of agglomeration and initial film density. The films were subsequently annealed at a range of temperatures from 100°C to 250°C to densify the films and increase conductivity. We show that, by reducing the degree of agglomeration in the films, sintering of LAMA-produced films occurs at low temperatures and results in near fully dense Ag films that exhibit an order of magnitude higher conductivity when compared to thick films produced by other techniques that are sintered at similar temperatures. Good agreement is observed between experiments and a sintering model that suggests that surface diffusion is dominant at temperatures below 150°C, and a combination of surface and grain boundary diffusion are responsible for sintering at slightly higher temperatures.