Sintering Metal Nanoparticle Films

We have carried out several measurements in order to understand the process of metal nanoparticle (MNP) film sintering. Small angle neutron scattering has been used to reveal the average diameters of silver and gold nanoparticles (Ag-NPs and Au-NPs) used in this study to be 4.6 and 3.8 nm, respectively, with a size distribution of ca. 20%. Spun- cast Ag-NP and Au-NP films have been sintered at temperature ranges of 80-160degC and 180-210 degC, respectively, for various times. The resulting film composition, morphology and electric resistance have been revealed. Upon sintering, the organic content in MNP films reduces to less than 10% while the overall film thickness reduces to about the half of the as-cast film thickness. The resistance of sintered Ag-NP films can vary over more than 7 decades depending on the sintering temperature. The conductivity of Ag-NP films sintered at 150degC is 2.4 times 10^-8 Omegam. The transport properties are affected by both the composition and morphology of sintered films.