"Chiral optical materials research will create new value across diverse fields including energy production, 3D displays, quantum networks, and diagnostics and treatment."
Professor Kim Dong-ha of Ewha Womans University's Department of Chemistry and Nanoscience, selected as the March recipient of the Korea Scientist and Engineer of the Month Award, described his research on chiral optical materials this way.
The award is hosted by the Ministry of Science and ICT and co-organized by the National Research Foundation of Korea and Seoul Economic Daily.
Chiral optical materials control light's rotational properties using "asymmetry (chirality)"—molecular structures that cannot be superimposed, like left and right hands.
"If we can precisely control light's rotation direction, we can expand into next-generation optical technologies that carry more information," Professor Kim said. "Chiral optical materials are not limited to displays but can extend to biomolecule recognition, bio-imaging, and precision treatment."
He added, "Our research team will continue producing universal research outcomes ranging from hydrogen production to cancer treatment."
Beyond basic information like intensity and color, light possesses a property of rotating in a spiral pattern as it travels. The same red light becomes a different signal depending on whether it rotates left or right. This is called "circularly polarized light." Professor Kim explained, "Controlling light's rotation direction adds another information axis to existing optical systems centered on color and brightness."
However, achieving this stably has long been a challenge. Creating light rotation requires molecular structures with inherent chirality, but conventional polymer-based chiral assembly methods saw structures easily rearrange with environmental changes. Achieving both strong circular polarization and high luminescence efficiency in the red spectrum was particularly difficult.
Professor Kim's team changed their approach. Securing assembly units that would not collapse was the core strategy. The team enhanced stability by utilizing unimolecular micelles formed by star-shaped block copolymers as structural scaffolds. They precisely bonded chiral molecules through multiple hydrogen bonds, designing a system where chirality information from small molecules is gradually transmitted and amplified through polymer chains to supramolecular structures.
As a result, the team successfully achieved strong and stable circularly polarized emission across the entire visible spectrum, including red. Structural stability was maintained for over 100 days at room temperature, with no optical performance degradation even after repeated heating and cooling cycles.
"The biggest differentiator is securing versatility to implement full-color circular polarization on the same platform regardless of emitter type," Professor Kim said. "Elucidating the hierarchical assembly mechanism through structural analysis and simulation together is also an important academic achievement."
Industrial impact is also anticipated. In displays, utilizing left and right circular polarization could enhance 3D precision and simplify processes that previously required separate optimization for each color. In security, different rotation information could be hidden within same-colored light to implement multi-layer authentication. In optical communications and sensors, it could reduce signal interference and improve channel discrimination.
Professor Kim clearly stated plans to expand applications to the bio field. Through catalyst research combining light rotation with plasmonics phenomena, applications in hydrogen production and cancer treatment are possible. When light of specific wavelengths is applied, strong electric fields and charges form on nanomaterial surfaces, which can operate differently across distinct domains—from energy production to tumor cell destruction.
"It's fascinating that one material design principle can simultaneously apply to completely different fields like energy and bio," Professor Kim said.
The research was published in the international journal Science in August last year, receiving recognition for its achievements.
"The chiral supramolecular co-assembly research results were derived through collaboration with researchers who conducted joint research over a long period," Professor Kim said. "To conduct interdisciplinary and convergent research, individual capabilities of the principal investigator are required, but it is also important to secure collaborators and build and maintain harmonious relationships with them."