Evaporation-driven nanoparticles motion and deposition on a textured surface in the inkjet process

Abstract

The evaporation-driven motion and deposition dynamics of nanoparticles (NPs) play significant roles in inkjet-printed structures such as the finger electrodes of solar cells. The objective of the present work is to reveal the mechanisms of NPs motion and distribution on a textured surface in the multi-droplets impact, coalescence and evaporation process. However, the complex interplay among NPs, host fluids and textured medium presents great challenges to numerical modeling. In this paper, a hybrid 3D lattice Boltzmann (LB) model coupled with the Langevin equation (LE) model is presented to handle the multi-droplets impact, coalescence, evaporation and NPs motion dynamics. In the droplet evaporation process, two patterns of NPs deposition rate are first identified at the time of maximum spreading width. For simultaneous and successive impact modes, three peaks of deposited NPs are formed adjacent to the droplet centers after drying out. And the quantities of deposited NPs adjacent to the collision region are increased due to enhanced NPs mixing in successive impacts mode. Detailed figures of NPs motion and deposition on a textured surface are offered that provide in-depth insights beneficial for optimizing the inkjet printing process.