M2 高橋達弥君と大久哲助教の熱活性化遅延蛍光材料ホストを用いた塗布型リン光タンデム素子の研究に関する「An Indolocarbazole-Based Thermally Activated Delayed Fluorescence Host for Solution-Processed Phosphorescent Tandem Organic Light-Emitting Devices Exhibiting Extremely Small Efficiency Roll-Off」と題する論文が Wiley の Advanced Functional Materials (IF: 13.325) に受理されました！
Title: An Indolocarbazole-Based Thermally Activated Delayed Fluorescence Host for Solution-Processed Phosphorescent Tandem Organic Light-Emitting Devices Exhibiting Extremely Small Efficiency Roll-Off
By S. Ohisa*, T. Takahashi, M. Igarashi, H. Fukuda, T. Hikichi, R. Komatsu, E. Ueki, Y.-J. Pu*, T. Chiba, J. Kido*, Adv. Funct. Mater. 2019, accepted.
Abstract: We report the development of a solution-processed phosphorescent tandem organic light-emitting device (OLED) exhibiting extremely small efficiency roll-off. The OLED comprises two light-emitting units (LEUs) connected by an interconnecting unit (ICU) and employs a thermally activated delayed fluorescence host material. One of the most difficult tasks in the fabrication of OLEDs is to form a multi-layer structure without dissolving the underlayer during the coating of the upper layer. The developed host materials exhibited high tolerance to methanol. The upper-layer adjacent to the light-emitting layer consists of ZnO nanoparticles, which could be dispersed in methanol by improving the preparation method. As a result, we succeeded in the fabrication of a solution-processed phosphorescent tandem OLED comprising two LEUs. The maximum external quantum efficiency (EQE) of the tandem device was 22.8%, and the EQE was 21.9% even at a high luminance of 10,000 cd/m2. The suppression of efficiency roll-off is among the best of those previously reported. Moreover, the operational stability of the tandem device was much higher compared with single-LEU devices.