華南理工大学 (SCUT) の蘇教授 (Prof. Shi-Jian Su)、劉博士 (Dr. Ming Liu) との水平配向性棒状発光分子による外部量子効率35%の実現に関する「Horizontally Orientated Stick-like Emitters: Enhancement of Intrinsic Out-coupling Factor and Electroluminescence Performance」と題する共同研究論文がアメリカ化学会 (ACS) の Chemistry of Materials (IF: 9.466) の今月の Most read article に選出されました。
スピロビアクリジンをドナー部位として用い、水平配向度90%、光取出技術なしに、外部量子効率35% を実現する一連の水平配向性TADF材料群の開発に成功しています。本研究は、ROEL の横山大輔准教授、INOEL の硯里善幸准教授にも有機固体薄膜中の分子配向評価・解析の面からご協力頂きました！
Abstract: Highly efficient organic light-emitting diodes are in urgent demand in applications of new generation full-color displays and solid-state lighting sources. The limitation of device performance is greatly affected by extrinsic and intrinsic elements of the light out-coupling process. By elaborately designing emitters as sticklike molecules, horizontal orientation ratios in the range of 86–93% were realized to intrinsically increase the out-coupling factor of electroluminescence devices. These elongated compounds are inclined to lie parallel to substrate in vacuum-deposited thin solid films and regularize their transition dipole moments in a major degree. As consequences of such desirable molecule arrangement, remarkable external quantum efficiencies near 21% for pure blue devices, close to 30% for sky-blue devices, and over 35% for greenish blue devices were respectively achieved. A compatible strategy on devising high-performance emitters for organic electroluminescence is advocated herein.
