Reduction of defects in self-assembling colloidal monolayer via surface modifiers and periodic mechanical vibration

Convective self-assembly has been demonstrated to be useful as a technique to generate self-assembled monolayers of nanoparticles over a given area. These films, however, suffer from defects that occur with misaligned grain boundaries and point defects from missing particles. We demonstrate the effect of surfactant modified substrate and external mechanical vibration on reducing the inherent defects in colloidal monolayers obtained using an industrially scalable process: convective assembly. Surface modified substrates coupled with vibration during the deposition resulted in a higher degree of ordering over a large deposition area. Numerical investigation further shows the increased capability of these external modifiers helps in producing better quality films. A significant 86% reduction in the defects, with larger crystal domains are realized in comparison to control, enabling this technique to easily be scaled up for various industrial applications. [Display omitted] •Defects were reduced by combining mechanical vibration with surfactant-coated substrates.•A significant 86% reduction in the defects has been achieved.•Numerical investigation shows that these external modifiers are producing better quality films.•This particular technique may have potential implications for industrial utilization.