Korea University Produces World’s First Diamond Photonic Crystals for Displays and Energy Devices
Professor Lee Seung-woo’s group from the Department of Integrative Energy Engineering/KU-KIST Graduate School of Converging Science and Technology collaborated with Professor Tim Liedl’s group from the Ludwig-Maximilian-University Munich and successfully produced the world’s first diamond photonic crystals.
Photonic crystals, also referred to as semiconductors of light, have been widely used as core optical materials for color-type radiative coolers, image sensors, displays, solar cells, and lasers because they can reflect light in the desired wavelength band in all directions due to their photonic bandgap. Professor Eli Yablonovitch of UC Berkeley and others in the early and mid-1990s showed that the diamond lattice is the champion photonic crystal because it can open the widest optical band gap. It was then established in the early 2000s by Professor Edwin L. Thomas’ group from MIT that the direct rod-connected diamond lattice is the champion photonic crystal.
Nevertheless, this structure had never been produced in practice. Because diamond photonic crystals have a complex 3D structure, no production method other than the self-assembly of soft nanomaterials such as colloids is available. Moreover, because the volume fraction of the required structure is generally low (40% or less), the stability of the assembly is not sufficiently high.
In 2020, Professor Lee’s group theoretically demonstrated that direct rod-connected diamond photonic crystals have the potential to be produced from a soft nanomaterial called DNA origami, allowing the champion optical bandgap to be opened (https://doi.org/10.1021/acsabm.9b01171). In the present study, Professor Lee’s group and Professor Tim Liedl’s group experimentally produced the first direct rod-connected diamond photonic crystals and successfully demonstrated optical bandgap structure-based reflection in the infrared and visible light bandwidth. Their results represent a turning point for various innovative types of energy and display devices based on light–matter interactions.