城戸・笹部研 (フレックス大学院３年) の渡邊雄一郎さんのビピリジン骨格を有する新規電子輸送材料の論文が英国王立化学会(RSC) の J. Mater. Chem. C (IF: 4.696) にアクセプトされました。本研究は横山大輔准教授、片桐洋史准教授との共同研究です。
Syntheses, Properties, and OLED Characteristics of 2,2′-Bipyridine-Based Electron-Transport Materials: Synergistic Effect of Molecular Shape Anisotropy and a Weak Hydrogen-Bonding Network on Molecular Orientation
Y. Watanabe, H. Sasabe, D. Yokoyama, T. Beppu, H. Katagiri, J. Kido, J. Mater. Chem. C 2015, accepted.
Abstract: To boost the performances of OLEDs, one of the most promising approaches from a materials chemistry viewpoint is the use of thin solid films with horizontal molecular orientations. In this work, we developed 2,2′-bipyridine-skeleton-based electron-transport materials (ETMs) end-capped with 3,5-dipyridylphenyl groups with the objective of preparing films with horizontal molecular orientations for use in high-performance organic light-emitting devices (OLEDs). These compounds afforded highly oriented films and were used in fac-tris(2-phenylpyridine)iridium(III)-based OLEDs as an ETL. The optimized device exhibited low operating voltages of 2.8 and 3.2 V at luminances of 100 and 1000 cd m−2, respectively. At 1000 cd m−2, this device exhibited a power efficiency of 74 lm W−1 and an external quantum efficiency of 21%.