Unveiling van der Waals Colloidal Crystals: A New Frontier in Materials Science
Professor Lee Seung-woo’s group of the KU-KIST Graduate School of Converging Science and Technology developed a method for assembling colloidal crystals of a novel form using van der Waals force.
Colloidal crystals have been used as an essential material for E-ink. The newly developed van der Waals colloidal crystals feature the world’s highest reflectivity in the visible light region, and so the results are highly significant for the innovation of E-ink.
Professor Lee’s group successfully developed silica colloids including gold particles, optimized the van der Waals forces, and prepared the colloidal crystals in a fluid state. The results of the study showed that photonic crystals may be maintained through van der Waals forces in a liquid state, suggesting a new methodology for colloidal assembly.
The newly developed colloidal crystals can exhibit various colors based on the specific photonic bandgaps in the region of the visual light. The colloids developed by the group exhibit high efficiency and purity, and this is attributed to the perfect colloidal crystal structure and the gold particles.
The technology developed by the research group allows for the manufacture of displays of larger area than when using photonic crystals based on the conventional colloids, thereby providing a significant economic advantage. The colloids developed by the technology are an essential material for recently emerging fields such as E-ink. The high performance and resolution and the low power consumption supported by this new technology compared to existing E-ink materials suggest that the major limitations of E-ink technology may be overcome. Since the newly developed colloidal crystals allow for the implementation of various colors based on the photonic bandgaps, E-ink display color ranges can be extended, and their resolution improved.
One important feature of the technology is its excellent visibility. The van der Waals crystals can maintain excellent brightness and visibility even under strong sunlight, meaning that they can be applied to varied outdoor applications including outdoor signboards, traffic lights, and information displays. In addition, thanks to their enhanced color saturation, the colloidal crystals developed by the group are also capable of expressing clear and accurate colors even in outdoor spaces, thereby improving the color accuracy and quality of outdoor displays.