M2 荒木卓君 (Mr. Suguru Araki) と笹部久宏准教授の高効率・長寿命なTADF／リン光有機ELを実現するテトラジベンゾフラン誘導体ホール輸送材料群に関する論文が Wilely の Chem Eur J (IF: 5.236) に受理！荒木、おめでとう！本研究は山形大学横山研究室との共同研究です。横山先生、鮏川くん、ご協力ありがとうございました！
Title: Four dibenzofuran-terminated high triplet energy hole-transporters for high-efficiency and long-life organic light-emitting devices
By Hisahiro Sasabe,* Suguru Araki, Shoki Abe, Nozomi Ito, Kengo Kumada, Taito Noda, Yoshihito Sukegawa, Daisuke Yokoyama, and Junji Kido*, Chem. Eur. J. 2022, accepted.
Abstract: The weak stability of a hole-transporter upon approaching anion state is one of the major bottlenecks for developing long-life organic light-emitting devices (OLEDs). Therefore, in this study, we developed a series of thermally and electrically stable hole-transporters that are end-capped with four dibenzofuran units. These materials exhibit (i) high bond dissociation energy (BDE) toward anion state, (ii) high glass transition temperature (Tg >130 °C), and (iii) high triplet energy (ET >2.7 eV), thereby enabling approximately 20% high external quantum efficiency (EQE) and significantly prolonging the stability of both thermally activated delayed fluorescent (TADF) and phosphorescent OLEDs with an operation lifetime at 50% (LT50) of 20000–30000 h at 1000 cd m-2. In addition, investigating their structure-property relationship revealed that ionization potential (IP), BDE, and Tg are critical prerequisites for the hole- transporter to prolong lifetime in OLEDs.
