Prof. Joon Hak Oh of SNU Receives April 2025 'Scientist of the Month' Award
- Recognized for the Development of Chiral Organic Materials and Their Application in Advanced Optoelectronic Devices
- Establishing the Foundation for Commercialization of Next-Generation Optical Sensors and Optical Communication Technologies


▲ Professor Joon Hak Oh of the Department of Chemical and Biological Engineering, Seoul National University

Seoul National University College of Engineering announced that Professor Joon Hak Oh of the Department of Chemical and Biological Engineering has been selected as the April recipient of the “Scientist of the Month” award, jointly presented by the Ministry of Science and ICT (MSIT) and the National Research Foundation of Korea (NRF).

The “Scientist of the Month” award recognizes one outstanding researcher each month who has contributed to the advancement of science and technology through excellent R&D achievements. The recipient is awarded the Minister’s Commendation from the MSIT and a prize of 10 million KRW.

The MSIT and NRF noted that Professor Oh was highly commended for accelerating the practical application of next-generation optical sensors and optical communication technologies through his pioneering work in developing chiral organic optoelectronic materials and devices, a field still in its infancy globally.

Chirality refers to the property of asymmetry, where objects like the left and right hands are mirror images of each other but cannot be superimposed. Among chiral materials, those capable of manipulating the properties of light and electrons are called chiral optoelectronic materials. These materials can detect or emit light rotating in a specific direction, enabling precise control over light.

Due to these unique characteristics, chiral optoelectronic technologies have broad applications in cutting-edge fields such as 3D displays, virtual reality, high-precision sensors, bioimaging, and quantum computing. Consequently, there is active global research to develop chiral materials and devices and to explore their optical and electrical properties.

Traditionally, circular polarization control technologies have required separate components such as polarizers and wave plates, making miniaturization and integration of devices difficult. Various attempts have been made to overcome this limitation by developing chiral materials capable of detecting the rotation direction of light. However, most materials reported to date have exhibited low circular polarization detection sensitivity, complex fabrication processes, and high costs, limiting their practical application.


▲ Figure 1. Schematic illustration of helical polymer supramolecule and its application in photonic spin devices

To address these challenges, Professor Oh was the first to introduce the concept of supramolecular* chirality into organic optoelectronic devices and successfully observed enhanced chirality. He developed a method to add chiral dopants* to polymer semiconductors through a simple solution process, enabling the fabrication of helical supramolecular structures. The added materials could then be removed through simple thermal treatment after inducing the helical structures, without affecting the semiconductor’s performance.
* Supramolecular (structure): A material in which individual molecules come together naturally through weak interactions to form larger structures with new functions.
* Dopant: A substance added to materials like semiconductors to alter or enhance their properties.


▲ Figure 2. Schematic diagram of circularly polarized light detection device fabrication

Using these helical polymer supramolecular structures, Professor Oh developed world-class sensors capable of precisely detecting not only circularly polarized* light but also elliptically polarized light*, regardless of the angle of light incidence. Furthermore, he implemented an early prototype of a next-generation optical communication system and a real-time circular polarization detection and imaging system using these sensors.
* Circularly polarized light: Light that travels in a spiral motion and carries not only wavelength and intensity but also information about its rotational direction (spin angular momentum).
* Elliptically polarized light: A form of light that travels in a spiral pattern, but unlike circular polarization, its path traces an ellipse instead of a perfect circle.

The research was supported by the MSIT’s Mid-Career Researcher Program, the Basic Research Laboratory Program, and the Samsung Science & Technology Foundation. The results were published in Nature, a leading international journal, in May 2023.

Professor Oh stated, “This research is significant in that it presents a method to enhance the performance of chiral materials, and demonstrates practical fabrication techniques and potential applications for chiral optical devices, which had previously remained at the unit device level.” He added, “I will continue to pursue follow-up studies to contribute to national technological competitiveness and industrial advancement.”


[Reference Materials]
- Paper Title/Journal: “Helical polymers for dissymmetric circularly polarized light imaging”, Nature
- DOI: https://doi.org/10.1038/s41586-023-05877-0