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) に受理されました。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。一緒に研究を進めてくれた D3 小松龍太郎君 (Ryutaro Komatsu)、M2 堀田克之君 (Katsuyuki Hotta)、M2 佐藤守悟君 (Shugo Sato)、M1 加藤裕貴君 (Yuki Kato) 、おめでとうございます!
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。ご協力ありがとうございました!
Title: Horizontally Orientated Stick-like Emitters: Enhancement of Intrinsic Out-coupling Factor and Electroluminescence Performance
By Ming Liu, Ryutaro Komatsu, Xinyi Cai, Katsuyuki Hotta, Shugo Sato, Kunkun Liu, Dongcheng Chen, Yuki Kato, Hisahiro Sasabe,* Satoru Ohisa, Yoshiyuki Suzuri, Daisuke Yokoyama, Shi-Jian Su* and Junji Kido*, Chemistry of Materials, in press.
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 light out-coupling process. By elaborately designing emitters as stick-like molecules, horizontal orientation ratios in the range of 86-93% were realized to intrinsically increase out-coupling factor of electroluminescence devices. These elongated compounds are inclined to lie parallelly to substrate in vacuum deposited thin solid films and regularize their transition dipole moments in major degree. As consequences of such desirable molecule arrangement, remarkable external quantum efficiencies near 21% for pure blue device, close to 30% for sky-blue device and over 35% for greenish blue device were respectively achieved. A compatible strategy on devising high-performance emitters for organic electroluminescence is advocated herein.