Rapid fabrication of two- and three-dimensional colloidal crystal films via confined convective assembly

We have developed a self-assembly method for fabricating well-ordered two-dimensional (213) and three-dimensional (313) colloidal crystal films. With a minute amount of a polystyrene colloidal suspension and without any special equipment, the proposed method can be used to rapidly deposit high-quality colloidal crystal films over a large surface area. By controlling the lift-up rate of the substrate, we modulate the meniscus thinning rate, which determines whether the colloidal particles are assembled into two or three dimensions. The proposed method can be used to fabricate not only monolayered colloidal crystals with colloidal particles of various sizes, but also multilayered colloidal crystals. In addition, the method enables us to fabricate binary colloidal crystals by consecutively depositing large and small particles.