笹部研究室の M2 郡悠真君、笹部久宏准教授の「りん光増感剤とMR-TADF発光材料を用いた緑色ハイパー有機 EL の長寿命化におけるホール輸送材料／発光層界面の重要性」の論文が RSC の J. Mater. Chem. C (IF: 5.7) に受理されました。

本研究は、JSPS 科研費（基盤研究B 23H02032）、NEDO 官民による若手研究者発掘支援事業 (21502128-0) の助成を受けたものです。

Title: Critical Importance of the Hole-Transporter and Emission Layer Interface for Prolonging Lifetime in Phosphor- Sensitized Hyper OLED based on MR-TADF emitter
By Yuma Kori, Haruki Nemma, Jiang Dehao, Naoki Meguro, Ryunosuke Mimura, Junji Kido, and Hisahiro Sasabe*, J. Mater. Chem. C accepted.

Abstract: Multiresonance thermally activated delayed fluorescence (MR-TADF) technology has garnered significant attention because MR-TADF emitter enables both high efficiency and high color purity, making them ideal for next-generation high-resolution displays. However, the lifetime of MR-TADF-based OLED remains considerably lower than that of phosphorescent and conventional TADF counterparts. To address this challenge, we focused on (i) a phosphor-sensitized hyper OLED system to improve both the efficiency and the lifetime, and (ii) the interface between the hole-transport layer (HTL) and the emission layer (EML). This interface was found to be crucial for achieving both high efficiency and long operational lifetimes in MR-TADF-based hyper OLEDs. By employing a HTL with a deep ionization potential, which prevents hole accumulation at the HTL/EML interface and direct carrier trapping on the MR-TADF emitter, we successfully extended the lifetime of phosphor-sensitized hyper OLEDs based on MR-TADF emitters. Consequently, we realized green hyper OLEDs with CIE coordinates of (0.31, 0.66), an external quantum efficiency of 28.1%, a power efficiency of 159.9 lm W-1, and operation lifetimes at 95/90% of the initial luminance of 1000 cd m−2 (LT95/90) of over 600/2400 hours at a high brightness of 1000 cd m-2. These performances are among the best reported in scientific literature.

https://hisahirosasabe.yz.yamagata-u.ac.jp/archives/420