Princeton University

School of Engineering & Applied Science

Exciton management in OLEDs and future organic laser diodes

Professor Chihaya Adachi, Kyushu University
Engineering Quadrangle, B418
Tuesday, March 14, 2017 - 1:00pm

While the demonstration of the first OLED emitting thermally activated delayed fluorescence (TADF) in Advanced Materials1-3 in 2009 by our group gave a glimpse of TADF's potential, our successive report in Nature4-6 in 2012 of a TADF-based OLED with an internal quantum efficiency of nearly 100% grabbed the attention of researchers world-wide and established TADF as a truly promising technology. In the first half, recent progress on TADF OLEDs will be discussed from the aspect of electroluminescence quantum efficiency and device stability.
In the second half, I will introduce our recent efforts to inject high current density, reduce roll-off related to Joule heating and various exciton annihilation processes,7-9 and control excited-state absorption for the realization of electrically pumped organic semiconductor laser diodes. By managing these issues, we report low-threshold surface-emitting organic distributed feedback lasers operating under continuous-wave photoexcitation for 30 ms.10

[1] Ayataka Endo, Mai Ogasawara, Atsushi Takahashi, Daisuke Yokoyama, Yoshimine Kato, Chihaya Adachi, Adv. Mater., 21, 4802, 2009 [2] Ayataka Endo, Keigo Sato, Kazuaki Yoshimura, Takahiro Kai, Atsushi Kawada, Hiroshi Miyazaki, Chihaya Adachi, Appl. Phys. Lett., 98, 083302, 2011 [3] Kenichi Goushi, Kou Yoshida, Keigo Sato, Chihaya Adachi, Nat. Photon., 6, 253, 2012 [4] Hiroki Uoyama, Kenichi Goushi, Katsuyuki Shizu, Hiroko Nomura, Chihaya Adachi, Nature, 492, 234, 2012 [5] Hajime Nakanotani, Takahiro Higuchi, Taro Furukawa, Kensuke Masui, Kei Morimoto, Masaki Numata, Hiroyuki Tanaka, Yuta Sagara, Takuma Yasuda, Chihaya Adachi, Nat. Commun., 5, 4016, 2014, [6] H. Nakanotani, T. Furukawa, C. Adachi, Adv. Opt. Mater. 3, 10, 2015. [7] H. Kuwae, A. Nitta, K. Yoshida, T. Kasahara, T. Matsushima, M. Inoue, S. Shoji, J. Mizuno, C. Adachi, J. Appl. Phys. 118, 155501, 2015 [8] M. Inoue, T. Matsushima, H. Nakanotani, C. Adachi, Chem. Phys. Lett., 624, 46, 2015 [9] K. Hayashi, H. Nakanotani, M. Inoue, K. Yoshida, O. Mikhnenko, T.-Q. Nguyen, C. Adachi, Appl. Phys. Lett. 2015, 106, 0933301 [10] Atula S. D. Sandanayaka; Kou Yoshida; Munetomo Inoue; Chuanjiang Qin; Kenichi Goushi; Jean-Charles Ribierre; Toshinori Matsushima; Chihaya Adachi, Adv. Opt. Mat., 4, 6, 834, 2016