2016年第63回応用物理学会春季学術講演会

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一般セッション(口頭講演)

12 有機分子・バイオエレクトロニクス » 12.4 有機EL・トランジスタ

[20p-W521-1~16] 12.4 有機EL・トランジスタ

2016年3月20日(日) 13:45 〜 18:15 W521 (西5号館)

梶井 博武(阪大)、深川 弘彦(NHK技研)、村田 英幸(北陸先端大)

14:30 〜 14:45

[20p-W521-4] Horizontal molecular orientation in solution-processed glassy organic thin films based on oligofluorene derivatives

〇(D)Zhao Li1、Komino Takeshi1,2,3、Inoue Munetomo1、Kim Ju-Hyung1、Ribierre Jean-Charles1,3、Adachi Chihaya1,2,3 (1.OPERA, Kyushu University、2.Education Center for Global Leaders in Molecular System for Devices, Kyushu University、3.ERATO, JST)

キーワード:Solution-process,Molecular orientation,OLEDs

Horizontal molecular orientation in organic light-emitting diode (OLED) materials has been already reported in a variety of vacuum-deposited glassy thin films. It is now well-established that such a horizontal molecular orientation is essential to improve the light outcoupling efficiency and the overall performance of the light-emitting devices. However, this preferential orientation has not been observed so far in spin-coated glassy organic films. Because of the current need to develop high performance solution-processed OLEDs for low cost and large area applications, control of the molecular orientation in spin-coated glassy organic thin films is a critical issue for improving the OLED performance. Here, we show that the horizontal orientation of light-emitting molecules can be obtained in spin-coated glassy thin films based on a blend of a heptafluorene derivative in a 4,4’- bis(N-carbazolyl)-1,1’-biphenyl (CBP) host. Variable angle spectroscopic ellipsometry and angle dependent photoluminescence measurements are carried out to investigate the molecular orientation in the heptafluorene neat films and in CBP blends. Solution-processed fluorescent OLEDs with horizontally oriented heptafluorene emitters are then fabricated and exhibit deep blue electroluminescence with an external quantum efficiency as high as 5.3 %.