title: Triarylboron-Based Fluorescent Organic Light-Emitting Diodes with External Quantum Efficiencies Exceeding 20 .
abstract: Triarylboron compounds have attracted much attention, and found wide use as functional materials because of their electron-accepting properties arising from the vacant p orbitals on the boron atoms. In this study, we design and synthesize new donor-acceptor triarylboron emitters that show thermally activated delayed fluorescence. These emitters display sky-blue to green emission and high photoluminescence quantum yields of 87-100 % in host matrices. Organic light-emitting diodes using these emitting molecules as dopants exhibit high external quantum efficiencies of 14.0-22.8 %, which originate from efficient up-conversion from triplet to singlet states and subsequent efficient radiative decay from singlet to ground states.
authors.affiliation: Institute for Chemical Research Kyoto University, Uji, Kyoto 611-0011 (Japan).
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Institute for Chemical Research Kyoto University, Uji, Kyoto 611-0011 (Japan).
authors.forename: Shosei
authors.initials: S
authors.lastname: Kubo
authors.affiliation: Institute for Chemical Research Kyoto University, Uji, Kyoto 611-0011 (Japan).
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Shizu
authors.affiliation: Institute for Chemical Research Kyoto University, Uji, Kyoto 611-0011 (Japan).
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fukushima
authors.affiliation: Institute for Chemical Research Kyoto University, Uji, Kyoto 611-0011 (Japan).
authors.forename: Atsushi
authors.initials: A
authors.lastname: Wakamiya
authors.affiliation: Institute for Chemical Research Kyoto University, Uji, Kyoto 611-0011 (Japan).
authors.forename: Yasujiro
authors.initials: Y
authors.lastname: Murata
authors.affiliation: Center for Organic Photonics and Electronics Research, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan).|Japan Science and Technology Agency (JST), Exploratory Research for Advanced Technology (ERATO), Adachi Molecular Exciton Engineering Project, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan).
authors.forename: Chihaya
authors.initials: C
authors.lastname: Adachi
authors.affiliation: Institute for Chemical Research Kyoto University, Uji, Kyoto 611-0011 (Japan). kaji@scl.kyoto-u.ac.jp.
authors.forename: Hironori
authors.initials: H
authors.lastname: Kaji
keywords: boron; donor-acceptor systems; electroluminescence; fluorescence; organic light-emitting diodes