Investigation of sintering kinetics and morphological evolution of silver films from nano-dispersion

Abstract

The present study aimed at investigating the sintering kinetics and the mechanism of achieving uniform film morphology from silver nano-dispersion through evaporation of the solvent. A tuned time elapse between drop casting of silver dispersion and the annealing (dwell-time) acted as the decision maker in engineering the morphology: ring stain (infinite dwell-time), uniform deposit (variable dwell-time) and dot formation (zero dwell-time). Three distinct dwell-times (10, 20 and 30 min) are chosen for the study at different temperatures (120 to 250 C) and the conclusion is derived based on the profile of the deposit. The frozen morphology that resulted from the evaporation goes through the debonding of surfactant with simultaneous sintering to minimize the surface energy. A linear isothermal sintering model comprising initial grain size, grain growth parameter, annealing time and fractional porosity helps to predict the grain size post-annealing. Theoretical predictions of grain sizes are well matched with experimental ones. The grain growth parameter which shows an upward trend with the annealing temperature is mainly due to a reduction in the porosity and the increase in the fraction of solid solid interface which shows betterment in the percolation paths available for the movement of carriers. 2018, Springer-Verlag GmbH Germany, part of Springer Nature.