Fukuoka, Japan — Professor Chihaya Adachi , Director of the Center for Organic Photonics and Electronics Research (OPERA) and a Distinguished Professor at the Faculty of Engineering , Kyushu University, has been named a 2026 Clarivate Citation Laureate in Physics. The award recognizes his pioneering work on thermally activated delayed fluorescence (TADF), which established a new design principle for highly efficient organic light-emitting materials. The concept paved the way for the development of high-performance organic light-emitting diodes (OLEDs) without rare metals.
OLEDs are widely used in our lives, including smartphones, televisions, and other display devices. The first generation of OLED emitters used conventional fluorescent materials, which rely on singlet excitons and can theoretically utilize only about 25% of the excitons generated by electrical excitation. The second generation of emitters introduced phosphorescent materials containing heavy metals such as platinum and iridium, enabling nearly 100% exciton utilization for light emission. However, challenges remain, including the dependence on rare metals and limited operational stability, particularly for blue-emitting materials.
Against this backdrop, Adachi developed a new approach to harness both singlet and triplet excitons without relying on rare metals. The key was TADF, which uses thermal energy to convert non-emissive triplet excitons into emissive singlet excitons. TADF is now widely regarded as the third generation of OLED emission technology. Since Adachi’s pioneering work established the molecular design principles underlying TADF-based emitters, the field has grown into a major area of global research and development, accelerating advances in both fundamental science and commercial OLED technologies. Its potential extends beyond smartphone displays to wearable devices, automotive displays, and medical and healthcare technologies.
The Clarivate Citation Laureates Award honors researchers whose publications have demonstrated exceptional influence through citation impact and expert evaluation. On September 17, 2026, Clarivate announced 22 Citation Laureates across Physiology or Medicine, Physics, Chemistry, and Economics, recognizing their “Nobel-class” discoveries.
Adachi was recognized for establishing the molecular design principles that enable highly efficient TADF emission and for pioneering their development into practical OLED technologies, opening new possibilities for both research and industry.
Adachi shares this year’s recognition with Professor Stephen R. Forrest of the University of Michigan and Professor Mark E. Thompson of the University of Southern California, whose pioneering work established phosphorescent OLEDs as the second generation of OLED emission technology. Together, these second- and third-generation advances in organic light-emitting diode technology have enabled highly efficient and more sustainable display technologies that are widely used today.
“I am deeply honored to receive the Clarivate Citation Laureate Award,” Adachi says. “TADF emerged from a shift in perspective, finding ways to harness charge-transfer interactions once thought to limit light emission and considered detrimental, turning them into a mechanism for creating new emissive functions in organic molecules. This recognition reflects the contributions of many researchers, students, and collaborators who helped advance the field. It also motivates me to further develop TADF and hyperfluorescence technologies for next-generation OLEDs, and to explore new organic materials that contribute to both fundamental science and future industries.”
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Key publication: "Highly efficient organic light-emitting diodes from delayed fluorescence," Hiroki Uoyama, Kenichi Goushi, Katsuyuki Shizu, Hiroko Nomura, and Chihaya Adachi, Nature, https://doi.org/10.1038/nature11687
About Kyushu University
Founded in 1911, Kyushu University is one of Japan’s leading research-oriented institutions of higher education, consistently ranking as one of the top ten Japanese universities in the Times Higher Education World University Rankings and the QS World University Rankings. Located in Fukuoka, on the island of Kyushu—the most southwestern of Japan’s four main islands—Kyushu U sits in a coastal metropolis frequently ranked among the world’s most livable cities and historically known as Japan’s gateway to Asia. Its multiple campuses are home to around 19,000 students and 8,000 faculty and staff. Through its VISION 2030 , Kyushu U will “drive social change with integrative knowledge.” By fusing the spectrum of knowledge, from the humanities and arts to engineering and medical sciences, Kyushu U will strengthen its research in the key areas of decarbonization, medicine and health, and environment and food, to tackle society’s most pressing issues.