Research Director: Chihaya ADACHI
(Professor/Director, Center for Organic Photonics and Electronics Research (OPERA), Kyushu University)
Research Term: Dec 2013 - Mar 2019
Special Extension Period: Apr 2019 - Mar 2020
Grant Number: JPMJER1305

At present, organic optoelectronics has been greatly developed as a device that can withstand practical use, as represented by OLED, by using an organic ultrathin film of several hundred nm. OLEDs contain various exciton processes from charge injection/transport to exciton generation/deactivation processes after charge recombination. Also, from academic perspective, it is expected to deepen the field of organic photochemistry/physics. In this project, the thermally activated delayed fluorescence (TADF) technology developed by OPERA has been used as the basic science and technology, and we have advanced the elucidation of the spin conversion process along with the development of advanced TADF materials. In addition, the realization of an organic semiconductor laser, which is the ultimate organic light emitting device, was set as the first strategic goal of this project. From the material aspect, we have succeeded in creating robust organic laser molecules and novel NIR organic laser molecules. Further, we succeeded in qCW and current driven organic semiconductor lasers and we were able to open the beginning of the next generation organic optoelectronics. In addition, with the deepening of the understanding of the TADF phenomenon, organic CT states can be comprehensively understood, and by controlling the stability of the CT state, the room temperature luminous phenomenon has succeeded. In this project, while focusing on organic thin films, we are simultaneously studying the perovskite materials that have received a lot of attention in recent years, and innovative research results such as organic-inorganic hybrid LEDs, high-efficiency durable solar cells, and thick film devices were obtained.

The 5-year project deepens understanding of organic CT excited states, and new devices are expected to appear in the future. In addition, for organic semiconductor lasers, in order to promote commercialization, we launched a startup, "KOALA Tech Inc." In the future, we hope to advance the field of organic optoelectronics research to the next stage by promoting both basic research and applied device research.