Choi Soo-seok (최수석), a professor of electrical engineering at Pohang University of Science and Technology, has been selected as the winner of the South Korean Science and Technology Award for developing a technology that directly generates and changes colours and wavelengths across the entire visible spectrum.

The Ministry of Science and ICT and the National Research Foundation of Korea said on Tuesday that they had chosen Choi as the September recipient of the award.

Choi was recognised for developing “real full colour” technology that directly generates and changes colours and wavelengths across the entire visible spectrum using chiral nanostructures. Chiral nanostructures refer to structures that are mirror images like left and right hands but do not completely overlap, realised at the nanoscale.

Most displays and image sensors currently express colour by combining red (R), green (G) and blue (B). But the RGB method has limits because its structure is complex and it is difficult to directly implement or continuously change the diverse colours and wavelengths found in nature.

Choi drew on the principle by which butterflies and chameleons, among others, form nanostructures without pigments to create various structural colours. Based on that, he realised chiral nanostructures that can directly generate and control desired colours and wavelengths by adjusting the rotational length of nanomolecules without complex nanofabrication processes.

The structure forms a periodic optical structure through self-assembly in which molecules arrange themselves into a helix. Choi applied stretchable optoelectronic device technology to create an artificial electronic skin (Photonic E-Skin) whose colour changes depending on the direction and degree of stretching. He expanded the technology so the degree of deformation can be directly read and analysed through colour.

He also developed a low-voltage 2-volt variable colour filter that selectively implements desired colours by electrically adjusting the period of the nanostructure, and a colour tunable laser that can control colours in the visible spectrum. The laser can achieve high colour purity with a narrow linewidth at the 1-nanometre level, making it highly useful not only for displays but also for next-generation optical technologies such as augmented reality (AR) and holograms.

The related research results were published in international journals including Advanced Materials, Advanced Optical Materials and Laser & Photonics Reviews. Some studies were selected as cover papers in August 2023 and March this year.

Choi worked at LG Display for 19 years, experiencing the process complexity, light loss and colour-purity limitations of the RGB mixing method, and continued next-generation display research based on chiral nanostructures at POSTECH. To date, he has secured about 250 domestic and overseas patents, and recently has been expanding his research into multi-pixel and multi-colour control technology using the colour and pattern of light, polarisation and deformation.

Choi said, “I will expand the research to various optoelectronic fields, including next-generation displays and photonic semiconductors, AR and holograms.”